Rio Tinto (RTNTF) 20-F 2 Mar 21 2020 FY Annual report (foreign) Financial data

Cover

Cover	12 Months Ended
	Dec. 31, 2020shares
Document Information [Line Items]
Document Type	20-F
Document Registration Statement	false
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Document Shell Company Report	false
Entity File Number	001-10533
Entity Registrant Name	Rio Tinto plc
Entity Incorporation, State or Country Code	X0
Entity Address, Address Line One	6 St. James's Square
Entity Address, City or Town	London
Entity Address, Postal Zip Code	SW1Y 4AD
Entity Address, Country	GB
Title of 12(b) Security	American Depositary Shares
Trading Symbol	RIO
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding	1,255,756,296
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Accounting Standard	International Financial Reporting Standards
Entity Shell Company	false
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0000863064
Business Contact
Document Information [Line Items]
Entity Address, Address Line One	6 St. James's Square
Entity Address, City or Town	London
Entity Address, Postal Zip Code	SW1Y 4AD
Entity Address, Country	GB
Contact Personnel Name	Julie Parent
City Area Code	514
Local Phone Number	848-8519
Contact Personnel Email Address	julie.parent@riotinto.com
Rio Tinto Limited
Document Information [Line Items]
Entity File Number	001-34121
Entity Registrant Name	Rio Tinto Limited
Entity Incorporation, State or Country Code	C3
Entity Address, Address Line One	Level 7, 360 Collins Street
Entity Address, City or Town	Melbourne
Entity Address, Postal Zip Code	3000
Entity Address, Country	AU
Entity Common Stock, Shares Outstanding	371,216,214

Group income statement

Group income statement - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Consolidated operations
Consolidated sales revenue	$ 44,611	$ 43,165	$ 40,522
Net operating costs (excluding items shown separately)	(26,254)	(27,307)	(27,115)
Impairment charges	(904)	(3,487)	(132)
Net (losses)/gains on consolidation and disposal of interests in businesses	0	(291)	4,622
Exploration and evaluation costs	(625)	(624)	(488)
Profit relating to interests in undeveloped projects	1	10	278
Operating profit	16,829	11,466	17,687
Share of profit after tax of equity accounted units	652	301	513
Impairment of investments in equity accounted units	(339)	0	0
Profit before finance items and taxation	17,142	11,767	18,200
Finance items
Net exchange (losses)/gains on net external and intragroup debt balances	(1,124)	58	704
Net losses on derivatives not qualifying for hedge accounting	(123)	(68)	(57)
Finance income	141	300	249
Finance costs	(268)	(554)	(552)
Amortisation of discount	(377)	(384)	(377)
Net finance income (expense)	(1,751)	(648)	(33)
Profit before taxation	15,391	11,119	18,167
Taxation	(4,991)	(4,147)	(4,242)
Profit after tax for the year	10,400	6,972	13,925
Profit after tax for the year – attributable to owners of Rio Tinto (net earnings)	9,769	8,010	13,638
Profit after tax for the year – attributable to non-controlling interests	$ 631	$ (1,038)	$ 287
Basic earnings per share (in usd per share)	$ 6.040	$ 4.914	$ 7.932
Diluted earnings per share (in usd per share)	$ 5.998	$ 4.878	$ 7.876

Group statement of comprehensiv

Group statement of comprehensive income - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of comprehensive income [abstract]
Profit after tax for the year		$ 10,400	$ 6,972	$ 13,925
Items that will not be reclassified to profit or loss:
Actuarial (losses)/gains on post-retirement benefit plans		(474)	(262)	907
Changes in the fair value of equity investments held at fair value through other comprehensive income (FVOCI)		10	(5)	(13)
Tax relating to these components of other comprehensive income		112	83	(271)
Share of other comprehensive losses of equity accounted units, net of tax		(6)	(6)	(1)
Items that will not be reclassified to profit or loss		(358)	(190)	622
Items that have been/may be subsequently reclassified to profit or loss:
Currency translation adjustment	[1]	2,967	343	(3,830)
Currency translation on companies disposed of, transferred to the income statement		0	215	14
Fair value movements:
– Cash flow hedge gains		24	12	156
– Cash flow hedge (gains)/losses transferred to the income statement		(63)	(41)	40
Net change in costs of hedging	[2]	7	3	(39)
Tax relating to these components of other comprehensive loss/(income)		3	(6)	(54)
Share of other comprehensive income/(loss) of equity accounted units, net of tax		4	10	(48)
Other comprehensive income/(loss) for the year, net of tax		2,584	346	(3,139)
Total comprehensive income for the year	[3]	12,984	7,318	10,786
Total comprehensive income for the year - attributable to owners of Rio Tinto		12,201	8,351	10,663
Total comprehensive income for the year - attributable to non-controlling interests		$ 783	$ (1,033)	$ 123
[1]	Excludes a currency translation gain of US$333 million (2019: charge of US$29 million; 2018: charge of US$382 million) arising on Rio Tinto Limited’s share capital for the year ended 31 December 2020, which is recognised in the Group statement of changes in equity. Refer to Group statement of changes in equity on page 204.
[2]	As part of the 2018 bond buy-back programme, cross currency interest rate swaps hedging the bonds repurchased were closed out. This resulted in the reclassification of US$3 million from the cost of hedging reserve to finance costs in the income statement in 2018. There was no bond buy-back programme in 2019 or 2020.
[3]	Refer to Group statement of comprehensive income for further details. Adjustments to other reserves include currency translation attributable to owners of Rio Tinto, other than that arising on Rio Tinto Limited’s share capital.

Group statement of comprehens_2

Group statement of comprehensive income (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Statement of comprehensive income [abstract]
Currency translation gain (charge)	$ (382)	[1]
Reclassification of cost of hedging to income statement and recognised within finance costs	$ 3
[1]	Refer to note 1(d).

Group cash flow statement

Group cash flow statement - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of cash flows [abstract]
Cash flows from consolidated operations	[1]	$ 21,822	$ 19,705	$ 15,655
Dividends from equity accounted units		594	669	800
Cash flows from operations		22,416	20,374	16,455
Net interest paid		(569)	(537)	(612)
Dividends paid to holders of non-controlling interests in subsidiaries		(683)	(376)	(420)
Tax paid		(5,289)	(4,549)	(3,602)
Net cash generated from operating activities		15,875	14,912	11,821
Cash flows from investing activities
Purchases of property, plant and equipment and intangible assets		(6,189)	(5,488)	(5,430)
Disposals of subsidiaries, joint ventures, unincorporated joint operations and associates		10	(80)	7,733
Purchases of financial assets	[2]	(5)	(43)	(1,572)
Sales of financial assets	[2]	63	83	19
Sales of property, plant and equipment and intangible assets		45	49	586
Net funding of equity accounted units		(43)	(33)	(9)
Acquisitions of subsidiaries, joint ventures and associates		0	0	(5)
Other investing cash flows		(437)	11	(1)
Net cash (used)/generated in investing activities		(6,556)	(5,501)	1,321
Cash flows before financing activities		9,319	9,411	13,142
Cash flows from financing activities
Equity dividends paid to owners of Rio Tinto		(6,132)	(10,334)	(5,356)
Proceeds from additional borrowings		125	80	54
Repayment of borrowings	[3]	(721)	(203)	(2,300)
Lease principal payments		(324)	(315)	0
Proceeds from issue of equity to non-controlling interests		129	101	85
Own shares purchased from owners of Rio Tinto		(208)	(1,552)	(5,386)
Other financing cash flows		1	4	(48)
Net cash flows used in financing activities		(7,130)	(12,219)	(12,951)
Effects of exchange rates on cash and cash equivalents		165	(54)	151
Net increase/(decrease) in cash and cash equivalents		2,354	(2,862)	342
Opening cash and cash equivalents less overdrafts		8,027	10,889	10,547
Closing cash and cash equivalents less overdrafts		$ 10,381	$ 8,027	$ 10,889
[1]	(a) Cash flows from consolidated operations Profit after tax for the year 10,400 6,972 13,925 Adjustments for: – Taxation 4,991 4,147 4,242 – Finance items 1,751 648 33 – Share of profit after tax of equity accounted units (652) (301) (513) – Net losses/(gains) on consolidation and disposal of interests in businesses 36 — 291 (4,622) – Impairment charges of investments in equity accounted units after tax 6 339 — — – Impairment charges 6 904 3,487 132 – Depreciation and amortisation 4,279 4,384 4,015 – Provisions (including exchange differences on provisions) 894 753 1,011 Utilisation of provisions (582) (539) (620) Utilisation of provision for post-retirement benefits 25 (192) (205) (219) Change in inventories (281) 28 (587) Change in receivables and other assets (562) 163 (421) Change in trade and other payables 558 (191) 476 Other items (d) (25) 68 (1,197) 21,822 19,705 15,655
[2]	In 2020, the Group received net proceeds of US$58 million (2019 and 2018 net purchase of US$28 million and US$1.6 billion respectively) from its sales and purchases of investments within a separately managed portfolio of fixed income instruments. Purchases and sales of these securities are reported on a net cash flow basis within “Sales of financial assets” or “Purchases of financial assets” depending on the overall net position at each reporting date.
[3]	On 11 May 2020, we repaid our €402 million (nominal value) Rio Tinto Finance plc Euro Bonds on their maturity. The cash outflow relating to the repayment of the bonds and the realised loss on the derivatives have been recognised within "Repayment of borrowings and associated derivatives" in the Group cash flow statement and totalled US$526 million.

Group cash flow statement (Pare

Group cash flow statement (Parenthetical) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from consolidated operations
Profit after tax for the year		$ 10,400	$ 6,972	$ 13,925
Adjustments for:
– Taxation		4,991	4,147	4,242
– Finance items		1,751	648	33
– Share of profit after tax of equity accounted units		(652)	(301)	(513)
– Net losses/(gains) on consolidation and disposal of interests in businesses		0	291	(4,622)
– Impairment charges of investments in equity accounted units after tax		339	0	0
– Impairment charges		904	3,487	132
– Depreciation and amortisation		4,279	4,384	4,015
– Provisions (including exchange differences on provisions)		894	753	1,011
Utilisation of provisions		(582)	(539)	(620)
Utilisation of provision for post-retirement benefits		(192)	(205)	(219)
Change in inventories		(281)	28	(587)
Change in receivables and other assets		(562)	163	(421)
Change in trade and other payables		558	(191)	476
Other items	[1]	(25)	68	(1,197)
Purchases of financial assets	[2]	5	43	1,572
Adjustments for derivative contracts transacted and not designated for hedge relationship				288
Adjustments to add back gain on sale of surplus land at Kitmat				549
Revaluation of a financial asset				167
Fixed Income Instruments [Member]
Adjustments for:
Purchases of financial assets		$ 58	$ 28	$ 1,600
[1]	In 2018 other items included adjustments to add back mark-to-market gains of US$288 million relating to derivative contracts transacted for operational purposes and not designated in a hedge relationship, a gain of US$549 million on the sale of surplus land at Kitimat and a gain of US$167 million on the revaluation of a financial asset arising from the disposal of the Mount Pleasant coal project in 2016.
[2]	In 2020, the Group received net proceeds of US$58 million (2019 and 2018 net purchase of US$28 million and US$1.6 billion respectively) from its sales and purchases of investments within a separately managed portfolio of fixed income instruments. Purchases and sales of these securities are reported on a net cash flow basis within “Sales of financial assets” or “Purchases of financial assets” depending on the overall net position at each reporting date.

Group balance sheet

Group balance sheet - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Non-current assets
Goodwill	$ 946	$ 922
Intangible assets	2,755	2,637
Property, plant and equipment	62,882	57,372
Investments in equity accounted units	3,764	3,971
Inventories	174	139
Deferred tax assets	3,385	3,102
Receivables and other assets	1,796	1,716
Tax recoverable	4	5
Other financial assets	829	635
Total non-current assets	76,535	70,499
Current assets
Inventories	3,917	3,463
Receivables and other assets	3,644	3,027
Tax recoverable	62	116
Other financial assets	2,851	2,670
Cash and cash equivalents	10,381	8,027
Total current assets	20,855	17,303
Total assets	97,390	87,802
Current liabilities
Borrowings and other financial liabilities	(607)	(1,372)
Trade and other payables	(7,421)	(6,480)
Tax payable	(1,850)	(1,874)
Provisions including post-retirement benefits	(1,729)	(1,399)
Total current liabilities	(11,607)	(11,125)
Non-current liabilities
Borrowings and other financial liabilities	(13,408)	(13,341)
Trade and other payables	(820)	(794)
Tax payable	(477)	(376)
Deferred tax liabilities	(3,239)	(3,220)
Provisions including post-retirement benefits	(15,936)	(13,704)
Total non-current liabilities	(33,880)	(31,435)
Total liabilities	(45,487)	(42,560)
Net assets	51,903	45,242
Capital and reserves
Share premium account	4,314	4,313
Other reserves	11,960	9,177
Retained earnings	26,792	23,387
Equity attributable to owners of Rio Tinto	47,054	40,532
Attributable to non-controlling interests	4,849	4,710
Total equity	51,903	45,242
Rio Tinto plc
Capital and reserves
Share capital	207	207
Rio Tinto Limited
Capital and reserves
Share capital	$ 3,781	$ 3,448

Group statement of changes in e

Group statement of changes in equity - USD ($) $ in Millions		Total	Share capital	Share premium	Other reserves	Retained earnings	Total	Non-controlling interests
Adjustment for transition to new accounting pronouncements	[1]	$ (169)			$ 10	$ (179)	$ (169)
Opening balance at Dec. 31, 2017		51,115	$ 4,360	$ 4,306	12,284	23,761	44,711	$ 6,404
Restated opening balance at Dec. 31, 2017		50,946	4,360	4,306	12,294	23,582	44,542	6,404
Total comprehensive income/(loss)	[2]	10,786			(3,600)	14,263	10,663	123
Currency translation arising on Rio Tinto Limited's share capital	[3]	(382)	(382)				(382)
Dividends paid		(5,771)				(5,356)	(5,356)	(415)
Share buy-back	[4]	(5,704)	(290)		9	(5,423)	(5,704)	0
Own shares purchased from Rio Tinto shareholders to satisfy share options	[5]	(254)			(114)	(140)	(254)
Change in equity interest held by Rio Tinto		0			0	60	60	(60)
Treasury shares reissued and other movements		6		6			6
Equity issued to holders of non-controlling interests		85						85
Employee share options and other IFRS 2 charges to the income statement		111			50	61	111
Transfers and other movements		0			22	(22)
Closing balance at Dec. 31, 2018		49,823	3,688	4,312	8,661	27,025	43,686	6,137
Adjustment for transition to new accounting pronouncements	[6]	(115)			0	(113)	(113)	(2)
Restated opening balance at Dec. 31, 2018		49,708	3,688	4,312	8,661	26,912	43,573	6,135
Total comprehensive income/(loss)	[2]	7,318			519	7,832	8,351	(1,033)
Currency translation arising on Rio Tinto Limited's share capital	[3]	(29)	(29)				(29)
Dividends paid		(10,710)				(10,334)	(10,334)	(376)
Share buy-back	[4]	(1,135)	(4)		4	(1,135)	(1,135)
Companies no longer consolidated		(32)						(32)
Own shares purchased from Rio Tinto shareholders to satisfy share options	[5]	(106)			(63)	(43)	(106)
Change in equity interest held by Rio Tinto		0				85	85	(85)
Treasury shares reissued and other movements		1		1			1
Equity issued to holders of non-controlling interests		101						101
Employee share options and other IFRS 2 charges to the income statement		126			56	70	126
Closing balance at Dec. 31, 2019		45,242	3,655	4,313	9,177	23,387	40,532	4,710
Total comprehensive income/(loss)	[2]	12,984			2,798	9,403	12,201	783
Currency translation arising on Rio Tinto Limited's share capital	[3]	333	333				333
Dividends paid		(6,821)				(6,132)	(6,132)	(689)
Share buy-back	[4]	1	0		0	(1)	(1)
Own shares purchased from Rio Tinto shareholders to satisfy share options	[5]	(107)			(76)	(31)	(107)
Change in equity interest held by Rio Tinto		0				84	84	(84)
Treasury shares reissued and other movements		1		1			1
Equity issued to holders of non-controlling interests		129						129
Employee share options and other IFRS 2 charges to the income statement		143			61	82	143
Closing balance at Dec. 31, 2020		$ 51,903	$ 3,988	$ 4,314	$ 11,960	$ 26,792	$ 47,054	$ 4,849
[1]	impact of the transition to new accounting pronouncements; IFRS 9 “Financial Instruments” and IFRS 15 "Revenue from Contracts with Customers" on 1 January 2018.
[2]	Refer to Group statement of comprehensive income for further details. Adjustments to other reserves include currency translation attributable to owners of Rio Tinto, other than that arising on Rio Tinto Limited’s share capital.
[3]	Refer to note 1(d).
[4]	In 2020, the amount of US$1 million together with the amounts paid during the year in respect of an irrevocable contract in place at the beginning of the year to cover the share buy-back programme totalled US$208 million as reported in the cash flow statement. In 2019, the total amount of US$1,135 million (2018: US$5,704 million) included own shares purchased from the owners of Rio Tinto as per the cash flow statement of US$1,552 million (2018: US$5,386 million) and a financial liability recognised in respect of an irrevocable contract in place as at the reporting date to cover the share buy-back programme, less amounts paid during the year in respect of a similar irrevocable contract in place at the beginning of the year.
[5]	Net of contributions received from employees for share awards and share options.
[6]	Impact of the transition to new accounting pronouncements; IFRS 16 “Leases” and IFRIC 23 "Uncertainty over income tax treatments" on 1 January 2019.

Group statement of changes in_2

Group statement of changes in equity (Parenthetical) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share buy-back	[1]	$ 1	$ (1,135)	$ (5,704)
Own shares purchased from owners of Rio Tinto		$ 208	$ 1,552	$ 5,386
[1]	In 2020, the amount of US$1 million together with the amounts paid during the year in respect of an irrevocable contract in place at the beginning of the year to cover the share buy-back programme totalled US$208 million as reported in the cash flow statement. In 2019, the total amount of US$1,135 million (2018: US$5,704 million) included own shares purchased from the owners of Rio Tinto as per the cash flow statement of US$1,552 million (2018: US$5,386 million) and a financial liability recognised in respect of an irrevocable contract in place as at the reporting date to cover the share buy-back programme, less amounts paid during the year in respect of a similar irrevocable contract in place at the beginning of the year.

Principal accounting policies

Principal accounting policies	12 Months Ended
	Dec. 31, 2020
Disclosure of initial application of standards or interpretations [abstract]
Principal accounting policies	1 Principal accounting policies Corporate information Rio Tinto’s business is finding, mining and processing mineral resources. Major products are aluminium, copper, diamonds, gold, industrial minerals (borates, titanium dioxide and salt), iron ore and uranium. Activities span the world and are strongly represented in Australia and North America, with significant businesses also in Asia, Europe, Africa and South America. Rio Tinto plc is incorporated in the UK and listed on the London and New York Stock Exchanges and Rio Tinto Limited is incorporated in Australia and listed on the Australian Stock Exchange. Rio Tinto plc’s registered office is at 6 St James’s Square, London SW1Y 4AD, UK. Rio Tinto Limited’s registered office is at Level 7, 360 Collins Street, Melbourne, Victoria 3000, Australia. For the purposes of preparing the IFRS compliant consolidated financial statements of the Rio Tinto Group, both the DLC companies, Rio Tinto plc and Rio Tinto Limited, are viewed as a single economic entity, and the interests of shareholders of both companies are presented as the equity interests of shareholders in the Rio Tinto Group. These financial statements consolidate the accounts of Rio Tinto plc and Rio Tinto Limited (together “the Companies”) and their respective subsidiaries (together “the Group”) and include the Group’s share of joint arrangements and associates as explained in note 1(b) below. The Group’s financial statements for the year ended 31 December 2020 were authorised for issue in accordance with a directors’ resolution on 22 February 2021. Notes 32 to 35 provide more information on the Group’s subsidiaries, joint arrangements and associates and note 39 provides information on the Group’s transactions with other related parties. The US dollar is the presentation currency used in these financial statements, as it most reliably reflects the Group’s global business performance. Basis of preparation of the financial statements The basis of preparation and the accounting policies used in preparing the Group’s 2020 financial statements are set out below. The financial statements have been prepared on a going concern basis in accordance with international accounting standards in conformity with the requirements of the Companies Act 2006 applicable to companies reporting under IFRS and in accordance with applicable UK law, applicable Australian law as amended by the Australian Securities and Investments Commission Order dated 24 July 2020, Article 4 of the European Union IAS regulation and also with: – International Financial Reporting Standards as issued by the International Accounting Standards Board (IASB) and interpretations issued from time to time by the IFRS Interpretations Committee (IFRS IC) both as adopted pursuant to Regulation (EC) No 1606/2002 as it applies in the European Union (IFRSs as adopted by the EU), and which are mandatory for EU reporting as at 31 December 2020; (EU IFRS) and – International Financial Reporting Standards as issued by the IASB and interpretations issued from time to time by the IFRS IC which are mandatory as at 31 December 2020 . The above accounting standards and interpretations are collectively referred to as “IFRS” in this report. The Group has not early adopted any amendments, standards or interpretations that have been issued but are not yet mandatory. The UK's transition period for leaving the EU ended on 31 December 2020. In accordance with consequent changes to applicable UK law, the Group will include the following in the basis of preparation for its 2021 financial statements: – International Financial Reporting standards as issued by the IASB and interpretations issued from time to time as adopted by the United Kingdom (UK). COVID-19 impact Despite various COVID-19 related challenges, the Group's assets have continued to operate, with our first priority being the protection of the health and safety of all our employees and communities. During the COVID-19 pandemic, the Group has implemented strict protocols globally across the business. These range from physical distancing, travel restrictions, roster changes and team splits, to flexible working arrangements, rapid screening and personal hygiene controls. The Group has delivered a good operational performance across most of our assets, catching up on planned maintenance activity in the second half of the year, particularly in iron ore, and continuing to adapt to new operating conditions as we learn to live with COVID-19. Recognising the broad and complex impacts of the pandemic on our markets, operations and financial performance, we have chosen not to segregate COVID-19 related costs from our underlying performance metrics. Going concern Management has prepared cash flow forecast scenarios that represent plausible downside scenarios to the business and global economy including the effects arising from the COVID-19 pandemic for a period of at least 12 months from the date of approval of the financial statements, which have been reviewed by the directors. These forecasts demonstrate that the Group has sufficient cash, other liquid resources and undrawn credit facilities to enable it to meet its obligations as they fall due. As such the directors considered it appropriate to adopt the going concern basis of accounting in preparing the full year financial information. Climate change The Group continues to develop its assessment of the potential impacts of climate change, the transition to a low-carbon future and our ambition to achieve net zero emissions across our operations by 2050. We framed the strategic context for the Group and our internal price setting process, including carbon price assumptions, through the lens of three plausible scenarios structured around the interplay of three global forces: Realpolitik, Society and Technology. – In Realpolitik, a fragmented world order, defined by strong nationalistic tendencies including structural tensions between the United States and China, holds back trade and global action on climate. Despite a low growth environment, global warming is on a path to reach or even exceed 3°C by 2100. Carbon prices remain low – in the range US$0-30/tCO 2 e. – In Society, strong global co-ordination of climate policies, supported by high and rising carbon prices (reaching US$130/tCO 2 e in developed countries by 2040), accelerates the energy transition. Despite stronger economic growth in low-income countries, global emissions peak and start to decline early, turning net-negative during the second half of the century, to meet the Paris goal of keeping temperature increases below 2°C. – In Technology, the fast roll-out of innovation provides both a strong boost to global economic productivity and decarbonisation efforts. But, without adequate policy support and with carbon prices remaining modest (US$15 to US$30/tCO 2 e by 2030) the decline in global emissions is insufficient to keep temperature increases below 2°C by 2100. Through our strategy process we test the resilience of our portfolio against each of these three scenarios. Overall, our portfolio is expected to perform more strongly in scenarios with proactive climate action, however we have not yet assessed the complete financial reporting consequences of a single Paris aligned scenario (more details on our portfolio scenario analysis can be found in our 2020 Climate Change report). The scenarios also inform the internal price setting process led by our Economics team. Those prices (including carbon) are used pervasively in our financial processes from budgeting, forecasting, capital allocation and project evaluation to the determination of Ore Reserves. In turn these prices are used to derive critical accounting estimates including as inputs to impairment testing (note 6), estimation of remaining economic life for units of production depreciation (note 1(i)) and discounting closure and rehabilitation provisions (note 25). As only one of the scenarios is aligned with the goals of the Paris Agreement, our internal carbon prices are not consistent with the expectation of climate policies required to accelerate the global transition to meet those goals. New standards issued The Group’s financial statements have been prepared on the basis of accounting policies consistent with those applied in the financial statements for the year ended 31 December 2019, except for the accounting requirements set out below, all of which were effective as at 1 January 2020 without restatement of prior years. The Group's accounting policies and critical accounting judgments have been updated to include the Group's approach to materiality upon implementation of "Definition of Material, Amendments to IAS 1 and IAS 8" (refer to "Materiality" below). The amendments do not affect the Group's approach to identifying and evaluating material transactions, or result in any change to policies and procedures for reviewing whether a disclosure or presentation is material. The IASB revised its Conceptual Framework which is mandatory in 2020. It is not a standard and does not override any standard, but its principles apply to arrangements not covered by IFRS standards. No arrangements have been identified which require a change in accounting treatment under the revised Conceptual Framework. The Group has adopted the definition of a business as required by "Definition of a business - amendments to IFRS 3" (refer to note 1b), Basis of consolidation, Acquisitions). Changes might result in future investment in new operations being accounted for as asset acquisitions rather than as business combinations, however no evaluation of a transaction under the amended IFRS 3 has been required in 2020. Standards issued, but not yet effective Interest Rate Benchmark Reform – Phase 2 (Amendments to IFRS 9, IAS 39, IFRS 7, IFRS 4 and IFRS 16, endorsed by the UK and mandatory in 2021) The amendments address the financial reporting impact from reform of the London Interbank Offered Rate (LIBOR) and other benchmark interest rates (collectively “IBOR reform”). Financial authorities have asked market participants to complete the transition to alternative Risk Free Rates (RFR) by the end of 2021. As part of the Group’s transition plan, a multidisciplinary working group continues to assess the impact of IBOR reform on systems, processes and financial reporting. The Group will take relevant Phase 2 practical reliefs from certain requirements in IFRS 9, IFRS 7, IFRS 4 and IFRS 16 relating to changes in the basis for determining contractual cash flows of financial assets, financial liabilities and hedge accounting. Based on the Group’s assessment we expect that the most significant practical impact from IBOR reform will be on our hedging arrangements and that this will arise from reform of US LIBOR. At 31 December 2020, the Group has interest rate risk exposure including US$7.3 billion nominal values of fixed-rate borrowings swapped to US dollar rates in fair value hedge relationships, described further in note 29 A (b) (v). It is anticipated that the Secured Overnight Financing Rate (SOFR) benchmark rate, recommended by the Alternative Reference Rates Committee, will be widely adopted by market participants and in practice will replace US LIBOR by the end of 2021. We expect application of the Phase 2 reliefs to result in continuation of the Group’s pre-existing hedge accounting upon amendment of designated arrangements in response to the replacement of IBOR with new benchmarks. The Group early adopted, in the financial statements for the year ended 31 December 2019, “Phase 1 - Amendments to IFRS 9, IAS 39, and IFRS 7- Interest rate benchmark reform”, which allowed temporary relief from applying specific hedge accounting requirements to hedging arrangements directly impacted by IBOR reform (refer to note 1 q (iv)). This temporary relief is expected to cease, on a hedge-by-hedge basis, when the designated hedge relationship is amended and application of Phase 2 reliefs begins. In addition, the Group has a number of arrangements which reference IBOR benchmarks and extend beyond 2021. These include third-party borrowings relating to the Oyu Tolgoi LLC project finance facility and other secured loans (refer to note 21), a number of intragroup balances and certain commercial contracts. Other arrangements which currently reference IBOR benchmarks include accessible revolving lines of credit (refer to note 29 A (b)), and shareholder loan facilities. Phase 2 amendments will require the Group to account for a change in the basis for determining the cash flows of a financial asset or a financial liability measured at amortised cost, by updating their respective effective interest rates as required by IBOR reform. As a result of the relief the Group expects that no significant gain or loss will arise from these updates. Property, Plant and Equipment: Proceeds before Intended Use (Amendments to IAS 16, mandatory in 2022 and not yet endorsed by the UK) Under the amendments the proceeds from selling items before the related item of property, plant and equipment is available for use should be recognised in profit or loss, together with the costs of producing those items. The impact from adoption is not currently expected to be material for the Group. Onerous Contracts – Cost of Fulfilling a Contract (Amendments to IAS 37, mandatory in 2022 and not yet endorsed by the UK) The amendments specify which costs an entity includes in determining the cost of fulfilling a contract for the purpose of assessing whether the contract is onerous. The Group is currently evaluating the impacts of this amendment. IFRS 17 Insurance Contracts and amendments to IFRS 17 Insurance Contracts (mandatory in 2023 and not yet endorsed by the UK) The standard provides consistent principles for all aspects of accounting for insurance contracts. The Group is currently evaluating the impact of this pronouncement. Amendments to IAS 1 "Presentation of financial statements" on classification of liabilities (mandatory in 2023 and not yet endorsed by the UK) Narrow-scope amendments to IAS 1 clarify that liabilities are classified as either current or non-current, depending on the rights that exist at the end of the reporting period. Classification is unaffected by the expectations of the entity or events after the reporting date. The Group is currently evaluating the impacts of this amendment. 1 Principal accounting policies continued Other standards The following new and amended standards are not expected to have a significant impact on the Group’s consolidated financial statements: COVID-19-Related Rent Concessions (Amendment to IFRS 16, effective in 2021), Reference to Conceptual Framework (Amendments to IFRS 3, effective in 2022) and Annual Improvements to IFRS Standards, (effective 2023). Judgments in applying accounting policies and key sources of estimation uncertainty The preparation of the financial statements requires management to use judgment in applying accounting policies and in making critical accounting estimates. These judgments and estimates are based on management’s best knowledge of the relevant facts and circumstances, having regard to previous experience, but actual results may differ materially from the amounts included in the financial statements. Areas of judgment in the application of accounting policies that have the most significant effect on the amounts recognised in the financial statements and key sources of estimation uncertainty that have a significant risk of causing a material adjustment to the carrying amounts of assets and liabilities within the next financial year are noted below and further information is contained in the accounting policies and/or the notes to the financial statements. These areas of judgment and estimation are discussed further in critical accounting policies and estimates on pages 219-222. The quantum of ore reserves and mineral resources impacts many of these areas and the basis of calculation is explained below. Information on less material judgments and sources of estimation uncertainty has been incorporated into the relevant accounting policy notes. Areas of judgment in the application of accounting policies that have the most significant effect on the amounts recognised in the financial statements in the current year are: – Impairment of non-current assets – determination of cash-generating units (CGUs) and assessment of indicators of impairment – note 1(e) and (i), critical policy (i), note 6, note 12 and note 13. – Estimation of asset lives – determination of the life of the orebody and mine reserves, including grade cut-off assumptions consistent with the internal prices described in the Climate Change section – note 1(i) and critical policy (ii). – Close-down, restoration and environmental obligations – determining when a closure study plan and cost estimate is sufficiently advanced and reliable to form the basis for an update – note 1(l) and critical policy (iii). – Deferral of stripping costs – judgment on components/strip ratios and separate or integrated multiple pit mines – note 1(h) and critical policy (iv). – Uncertain tax positions – technical interpretation of tax law and evaluation of outcomes in the determination of whether multiple or binary scenarios are the appropriate basis for provision measurement – note 1(n), critical policy (v), note 9 and note 30. – Recoverability of potential deferred tax assets – recognition of deferred tax assets for loss making operations – critical policy (vi) and note 17. Other areas of judgment impacting the financial statements are: – Provision for onerous contracts – determination of assets dedicated to a contract – note 1(i) and critical policy (vii). – Identification of functional currencies – different companies may make different judgments based on similar facts – note 1(d) and critical policy (viii). – Basis of consolidation – judgment as to when the Group has control, joint control or significant influence – critical policy (ix) and notes 32-35. – Contingencies – assessing the probability of any loss and whether it is possible to quantify any loss – critical policy (x) and note 30. – Exclusions from underlying earnings – judgment on items to be excluded on grounds of nature or size – critical policy (xi) and note 2. – Accounting for the Pilbara Iron Arrangements – treatment of payments made o ver a contractually specified period for network infrastructure capacity – critical policy (xiii) and note 33(c). Key sources of estimation uncertainty that have a significant risk of causing a material adjustment to the carrying amounts of assets and liabilities within the next financial year are: – Impairment of non-current assets – review of asset carrying values, impairment charges and reversals and the recoverability of goodwill – determination of discounted cash flows – note1(e) and (i), critical estimates (i), note 6, note 12 and note 13. – Close-down, restoration and environmental cost obligations – estimation of costs and the timing of expenditure – note 1(l), critical estimates (iii) and note 25. – Uncertain tax positions – estimating the potential exposures for each possible scenario – note 1(n), critical estimates (v), note 9 and note 30. – Recoverability of potential deferred tax assets – determination of cash flows – note 1(n), critical estimates (vi) and note 17. – Estimation of obligations for post-employment costs – note 1(o), critical estimates (xiv) and note 42. Materiality The Group considers information to be material if correcting a misstatement, omission or obscuring could, in the light of surrounding circumstances, reasonably be expected to change the judgment of a reasonable person relying on the financial statements. The Group considers both quantitative and qualitative factors in determining whether information is material; the concept of materiality is therefore not driven purely by numerical values. When considering the potential materiality of information, management makes an initial quantitative assessment using thresholds based on estimates of profit before taxation; for the year ended 31 December 2020 the quantitative threshold was US$550 million (year ended 31 December 2019: US$350 million based on underlying earnings). However, other considerations can result in a determination that lower values are material or, occasionally, that higher values are immaterial. These considerations include whether a misstatement, omission or obscuring: masks a change or trend in key performance indicators; causes reported key metrics to change from a positive to negative values or vice-versa; affects compliance with regulatory requirements or other contractual requirements; could result in an increase to management’s compensation; or might conceal an unlawful transaction. In assessing materiality, management also applies judgment based on its understanding of the business and its internal and external financial statement users. The assessment will consider user expectations of numerical and narrative reporting. Sources used in making this assessment would include, for example: published analyst consensus measures, experience gained in formal and informal dialogue with users (including regulatory correspondence), and peer group benchmarking. Ore reserves and mineral resources Estimates of ore reserves and, in some cases, mineral resources can impact: depreciation and amortisation rates; the carrying values of intangible assets and property, plant and equipment; deferred stripping costs; provisions for close-down and restoration costs; and the recovery of deferred tax assets. The Group estimates its ore reserves and mineral resources based on information compiled by Competent Persons as defined in accordance with the Joint Ore Reserves Committee (JORC) code (see note 1(j)). The estimation of ore reserves and mineral resources requires judgment to interpret available geological data and subsequently to select an appropriate mining method and then to establish an extraction schedule. Estimation requires assumptions about future commodity prices and demand, exchange rates, production costs, transport costs, close-down and restoration costs, recovery rates and discount rates and, in some instances, the renewal of mining licences. There are many uncertainties in the estimation process and assumptions that are valid at the time of estimation may change significantly when new information becomes available. New geological or economic data, or unforeseen operational issues, may change estimates of ore reserves and mineral resources. The Group uses judgment as to when to include mineral resources in accounting estimates, for example, the use of mineral resources in the Group’s depreciation policy is described in note 1(i) below and in the determination of the date of closure as described in note 1(l). For the purposes of disclosure only with this combined Annual Report on Form 20-F estimates of ore reserves have been computed in accordance with the SEC’s Industry Guide 7, rather than in accordance with the JORC code, and are shown on pages 341 to 347. This information is unaudited. Ore reserves presented in accordance with SEC Industry Guide 7 do not exceed the quantities that, it is estimated, could be extracted economically if future prices were to be in line with the average of historical prices for the three years to 30 June 2020, or contracted prices where applicable. For this purpose, contracted prices are applied only to future sales volumes for which the price is predetermined by an existing contract; and the average of historical prices is applied to expected sales volumes in excess of such amounts. Moreover, reported ore reserve estimates have not been increased above the levels expected to be economic based on Rio Tinto’s own long-term price assumptions. Therefore, a reduction in commodity prices from the three-year average historical price levels would not necessarily give rise to a reduction in reported ore reserves. (a) Accounting convention The financial information included in the financial statements for the year ended 31 December 2020, and for the related comparative periods, has been prepared under the historical cost convention, as modified by the revaluation of certain derivative contracts and financial assets, the impact of fair value hedge accounting on the hedged item and the accounting for post-employment assets and obligations. The Group’s policy in respect of these items is set out in the notes below. All financial statement values are rounded to the nearest million (US$m) unless otherwise stated. Where applicable, comparatives have been adjusted to measure or present them on the same basis as current period figures. (b) Basis of consolidation (notes 32-35) All intragroup transactions and balances have been eliminated on consolidation. Where necessary, adjustments are made to the locally reported assets, liabilities, and results of subsidiaries, joint arrangements and associates to bring their accounting policies in line with those used by the Group. Subsidiaries Subsidiaries are entities controlled by either of the companies. Control exists where either of the companies has: power over the entities, that is, existing rights that give it the current ability to direct the relevant activities of the entities (those that significantly affect the companies’ returns); exposure, or rights, to variable returns from its involvement with the entities; and the ability to use its power to affect those returns. Subsidiaries are fully consolidated from the date on which the Group obtains control. They are de-consolidated from the date that control ceases. Joint arrangements A joint arrangement is an arrangement in which two or more parties have joint control. Joint control is the contractually agreed sharing of control such that decisions about the relevant activities of the arrangement (those that significantly affect the companies’ returns) require the unanimous consent of the parties sharing control. The Group has two types of joint arrangements: Joint operations (JO) A JO is a joint arrangement in which the parties that share joint control have rights to the assets, and obligations for the liabilities, relating to the arrangement. This includes situations where the parties benefit from the joint activity through a share of the output, rather than by receiving a share of the results of trading. In relation to its interest in a JO, the Group recognises: its share of assets and liabilities; revenue from the sale of its share of the output and its share of any revenue generated from the sale of the output by the JO; and its share of expenses. All such amounts are measured in accordance with the terms of the arrangement, which is usually in proportion to the Group’s interest in the JO. These amounts are recorded in the Group’s financial statements on the appropriate lines. Joint ventures (JV) A JV is a joint arrangement in which the parties that share joint control have rights to the net assets of the arrangement. JVs are accounted for using the equity accounting method. Other unincorporated arrangements In some cases, the Group participates in unincorporated arrangements and has rights to its share of the assets and obligations for its share of the liabilities of the arrangement rather than a right to a net return, but does not share joint control. In such cases, the Group recognises: its share of assets and liabilities; revenue from the sale of its share of the output and its share of any revenue generated from the sale of the output by the unincorporated arrangement; and its share of expenses. All such amounts are measured in accordance with the terms of the arrangement, which is usually in proportion to the Group’s interest in the arrangement. These amounts are recorded in the Group’s financial statements on the appropriate lines. Associates An associate is an entity that is neither a subsidiary nor a joint arrangement, over which the Group has significant influence. Significant influence is presumed to exist where there is neither control nor joint control and the Group has over 20% of the voting rights, unless it can be clearly demonstrated that this is not the case. Significant influence can arise where the Group holds less than 20% of the voting rights if it has the power to participate in the financial and operating policy decisions affecting the entity. Investments in associates are accounted for using the equity accounting method. The Group uses the term “equity accounted units” (EAUs) to refer to associates and JVs collectively. Under the equity accounting method the investment is recorded initially at cost to the Group, including any goodwill on acquisition. In subsequent periods the carrying amount of the investment is adjusted to reflect the Group’s share of the EAUs’ retained post-acquisition profit or loss and other comprehensive income. Long-term loans to EAUs that in substance form part of the Group’s net investment (quasi equity loans) are financial assets but are included in the line “Investments in equity accounted units” on the face of the balance sheet. When the Group’s share of losses in an EAU equals or exceeds its interest in the EAU, including such long-term loans and any other unsecured receivables, the Group does not recognise further losses, unless it has incurred legal or constructive obligations to continue to make payments on behalf of the EAU. Acquisitions (note 36) Under the “acquisition” method of accounting for business combinations, the purchase consideration is allocated to the identifiable assets acquired and liabilities and contingent liabilities assumed (the identifiable net assets) on the basis of their fair value at the date of acquisition, which is the date on which control is obtained. In determining whether a particular set of activities is a business, an acquired arrangement has to have an input and substantive process which together significantly contribute to the ability to create outputs. 1 Principal accounting policies continued The consideration transferred for the acquisition of a subsidiary comprises the fair values of the assets transferred, the liabilities incurred to the former owners of the acquiree, the fair value of any asset or liability resulting from a contingent consideration arrangement and any equity interests issued by the Group. Costs related to the acquisition of a subsidiary are expensed as incurred. The excess of the consideration transferred, the amount of any non- controlling interest in the acquiree and the acquisition-date fair value of any previous equity interest in the acquiree over the fair value of the identifiable net assets acquired is recorded as goodwill. Any shortfall is immediately recognised in the income statement. Non-controlling interests in the acquiree, that are present ownership interests and entitle their holders to a proportionate share of the entity’s net assets in the event of liquidation, are recognised by the Group in one of two ways with the choice being available on an acquisition-by-acquisition basis. They can be measured at either the non-controlling interest’s proportionate share of the acquiree’s identifiable net assets or at fair value. In some cases, non-controlling interests may be treated as equity options and valued on that basis. Goodwill (see note 1(e)) and amounts attributable to non-controlling interests will differ depending on the basis used. Where the Group previously held a non-controlling interest in the acquiree, this is remeasured to fair value at the date control is obtained with any gain or loss recognised in the income statement. The cash cost of the share purchase that gives rise to control is included within “investing activities” in the cash flow statement. Where the Group increases its ownership interest in a subsidiary, the difference between the purchase price and the carrying value of the share of net assets acquired is recorded in equity. The cash cost of such purchases is included within “financing activities” in the cash flow statement. Provisional fair values allocated at a reporting date are finalised within 12 months of the acquisition date. The results of businesses acquired during the year are included in the consolidated financial statements from the date on which control, joint control or significant influence is obtained. Disposals (note 36) Individual non-current assets or “disposal groups” (that is, groups of assets and liabilities) to be disposed of by sale or otherwise in a single transaction are classified as “held for sale” if the following criteria are met at the period end: – The ca

Operating segments

Operating segments	12 Months Ended
	Dec. 31, 2020
Disclosure of operating segments [abstract]
Operating segments	2 Operating segments Rio Tinto’s management structure is based on the principal product groups (PG) together with global support functions whose leaders make up the Executive Committee. The Executive Committee members each report directly to the Chief Executive of Rio Tinto who is the chief operating decision maker (CODM) and is responsible for allocating resources and assessing performance of the operating segments. The CODM monitors the performance of each product group based on a number of measures, including underlying earnings, underlying EBITDA, capital expenditure, net cash generated from operating activities and free cash flow. Finance costs and net debt are managed on a group-wide basis. The Group's reportable segments are based on principal product groups and are consistent with the internal reporting structure as at 31 December 2020. Business units (BUs) are allocated to PGs based on management structure. The reportable segments are described as follows: Reportable segment Principal activities Iron Ore Iron ore mining and salt and gypsum production in Western Australia. Aluminium Bauxite mining; alumina refining; aluminium smelting. Copper & Diamonds Mining and refining of copper, gold, silver, molybdenum and other by-products; exploration activities. Also includes diamond mining, sorting and marketing. Energy & Minerals Includes businesses with products such as uranium, borates, titanium dioxide feedstock together with the Iron Ore Company of Canada (iron ore mining and iron concentrate/pellet production) and the Simandou iron ore project, which are the responsibility of the Energy & Minerals product group chief executive. The Group’s coal operations were included in Energy & Minerals until the divestment of these assets, which was completed during 2018. Following a reassessment in 2020 of the Group's reportable segments, Other Operations, which included our 100% interest in the Gove alumina refinery (in closure), Rio Tinto Marine, and the remaining legacy liabilities of Rio Tinto Coal Australia are separately shown from the above reportable segments as none of these operations met the quantitative thresholds to be reportable segments. The Underlying earnings and Underlying EBITDA of Rio Tinto Marine are attributed back to the product groups. Legacy operations are not an operating segment as they do not earn revenue and are not expected to do so in the future. Comparatives have been adjusted to ensure comparability with the current year disclosures. Other items includes amounts in relation to Group functions, unallocated corporate costs and central items. Gross product sales 2020 US$m 2019 US$m 2018 US$m Iron Ore 27,508 24,075 18,731 Aluminium 9,314 10,340 12,191 Copper & Diamonds 5,428 5,815 6,468 Energy & Minerals 5,014 5,150 5,451 Reportable segments total 47,264 45,380 42,841 Other Operations 18 18 9 Inter-segment transactions (264) (31) (15) Product group total 47,018 45,367 42,835 Share of equity accounted unit sales and adjustments for intra-subsidiary/equity accounted units sales (2,407) (2,202) (2,313) Consolidated sales revenue per income statement 44,611 43,165 40,522 Gross product sales includes the Group’s proportionate share of product sales by equity accounted units (after adjusting for sales to subsidiaries) of US$2,441 million (2019: US$2,234 million; 2018: US$2,354 million) which are not included in consolidated sales revenue. Consolidated sales revenue includes subsidiary sales of US$34 million (2019: US$32 million; 2018: US$41 million) to equity accounted units which are not included in gross product sales. Capital expenditure 2020 US$m 2019 US$m 2018 US$m Iron Ore 2,941 1,741 1,302 Aluminium 1,085 1,456 1,373 Copper & Diamonds 1,864 2,087 2,150 Energy & Minerals 428 551 442 Reportable segments total 6,318 5,835 5,267 Other Operations 2 (4) 12 Product group total 6,320 5,831 5,279 Other items 79 64 65 Less: capital expenditure of equity accounted units (255) (456) (500) Capital expenditure per financial information by business unit 6,144 5,439 4,844 Add back: proceeds from disposal of property, plant and equipment (a) 45 49 586 Capital expenditure per cash flow statement 6,189 5,488 5,430 (a) In 2018, proceeds from disposal of property, plant and equipment included US$508 million received on the sale of surplus land at Kitimat. Capital expenditure for reportable segments comprises the net cash outflow on purchases less disposals of property, plant and equipment, capitalised evaluation costs and purchases less disposals of other intangible assets. The details provided include 100% of subsidiaries’ capital expenditure and Rio Tinto’s share of the capital expenditure of joint operations and equity accounted units. Depreciation and amortisation 2020 US$m 2019 US$m 2018 US$m Iron Ore 1,838 1,723 1,702 Aluminium 1,191 1,312 1,122 Copper & Diamonds 1,153 1,320 1,317 Energy & Minerals 392 428 455 Reportable segments total 4,574 4,783 4,596 Other Operations 199 177 26 Product group total 4,773 4,960 4,622 Other items 82 77 43 Less: depreciation and amortisation of equity accounted units (576) (653) (650) Depreciation and amortisation per note 4 4,279 4,384 4,015 Product group depreciation and amortisation for reportable segments include 100% of subsidiaries’ depreciation and amortisation and Rio Tinto’s share of the depreciation and amortisation of equity accounted units. Rio Tinto’s share of the depreciation and amortisation charge of equity accounted units is deducted to arrive at depreciation and amortisation as shown in note 4. These figures do not include impairment charges and reversals, which are excluded from underlying earnings. Tax charge/(credit) 2020 US$m 2019 US$m 2018 US$m Iron Ore 5,035 4,198 2,830 Aluminium 320 211 532 Copper & Diamonds (238) 65 118 Energy & Minerals 360 411 500 Reportable segments total 5,477 4,885 3,980 Other Operations (7) (51) (51) Inter-segment transactions (24) (2) — Product group total 5,446 4,832 3,929 Other items (179) (67) (276) Exploration and evaluation not attributed to product groups (34) (83) (38) Net finance costs (38) (144) (174) 5,195 4,538 3,441 Tax (credit)/charge excluded from underlying earnings (204) (391) 801 Taxation per income statement 4,991 4,147 4,242 Tax charge/(credit) excludes amounts relating to equity accounted units. Further information on the tax charge/(credit) excluded from underlying earnings is provided in the section “Underlying earnings”, below. Underlying EBITDA 2020 US$m 2019 US$m 2018 US$m Iron Ore 18,837 16,098 11,378 Aluminium 2,152 2,285 3,095 Copper & Diamonds 2,172 2,073 2,776 Energy & Minerals 1,646 1,762 2,140 Reportable segments total 24,807 22,218 19,389 Other Operations — (77) (70) Inter-segment transactions (94) (9) — Product group total 24,713 22,132 19,319 Central pension costs, share-based payments and insurance 72 59 (128) Restructuring, project and one-off costs (133) (183) (272) Central costs (500) (496) (552) Exploration and evaluation not attributed to product groups (250) (315) (231) Underlying EBITDA 23,902 21,197 18,136 Impairment charges (1,272) (3,487) (132) Gains/(losses) on embedded commodity derivatives not qualifying for hedge accounting (including exchange) 6 (260) 279 Net (losses)/gains on consolidation and disposal of interests in businesses — (291) 4,622 Change in closure estimates (non-operating and fully impaired sites) (401) — (376) Gain on sale of wharf and land in Kitimat, Canada — — 602 Change in other exclusions — (171) — Items excluded from underlying EBITDA (1,667) (4,209) 4,995 Depreciation and amortisation in subsidiaries and equity accounted units (4,650) (4,925) (4,559) Taxation and finance items in equity accounted units (443) (296) (372) Finance items (1,751) (648) (33) Profit before taxation 15,391 11,119 18,167 2 Operating segments continued Underlying earnings 2020 US$m 2019 US$m 2018 US$m Iron Ore 11,398 9,638 6,531 Aluminium 471 599 1,347 Copper & Diamonds 763 554 1,054 Energy & Minerals 577 611 995 Reportable segments total 13,209 11,402 9,927 Other Operations (54) (89) (102) Inter-segment transactions (32) (3) — Product group total 13,123 11,310 9,825 Central pension costs, share-based payments and insurance 81 60 (90) Restructuring, project and one-off costs (108) (94) (190) Central costs (418) (550) (410) Exploration and evaluation not attributed to product groups (216) (231) (193) Net finance costs (14) (122) (134) Underlying earnings 12,448 10,373 8,808 Items excluded from underlying earnings (2,679) (2,363) 4,830 Net earnings attributable to owners of Rio Tinto per income statement 9,769 8,010 13,638 Underlying EBITDA and underlying earnings are reported by Rio Tinto to provide greater understanding of the underlying business performance of its operations and to enhance comparability of reporting periods. The measures of underlying EBITDA and underlying earnings, in conjunction with net cash generated from operating activities and capital expenditure (net of proceeds on disposals), are used by the Chief Executive of Rio Tinto to assess the performance of the product groups. Underlying earnings and net earnings both represent amounts net of tax attributable to owners of Rio Tinto. The following items are excluded from net earnings in arriving at underlying earnings in each period irrespective of materiality: – Net gains/(losses) on disposal of interests in businesses. – Impairment charges and reversals. – Profit/(loss) after tax from discontinued operations. – Exchange and derivative gains and losses. This exclusion includes exchange gains/(losses) on external net debt and intragroup balances, unrealised gains/(losses) on currency and interest rate derivatives not qualifying for hedge accounting, unrealised gains/(losses) on certain commodity derivatives not qualifying for hedge accounting, and unrealised gains/(losses) on embedded derivatives not qualifying for hedge accounting. In addition, there is a final judgmental category which includes, where applicable, other credits and charges that, individually or in aggregate with similar items, are of a nature or size to require exclusion in order to provide additional insight into underlying business performance. Underlying EBITDA excludes the EBITDA impact of the same items that are excluded from underlying earnings. Product group underlying earnings include the Group's share of the underlying earnings of subsidiaries and equity accounted units stated before finance items but after the amortisation of discount on provisions. Rio Tinto’s share of the underlying earnings of equity accounted units amounted to US$656 million in 2020 (2019: US$302 million; 2018: US$513 million). This amount is attributable as follows: US$640 million profit to the Copper & Diamonds product group and US$16 million profit to other product groups (2019: US$292 million profit to the Copper & Diamonds product group and US$10 million profit to other product groups; 2018: US$476 million profit to the Copper & Diamonds product group and US$37 million profit to other product groups). These amounts are included in underlying earnings and include the underlying earnings of the Group’s tolling entities which process alumina. Tolling entities recharge the majority of their costs and generally have minimal earnings. Reconciliation of underlying earnings to net earnings Pre-tax(h) Taxation 2020 US$m Non-controlling interests 2020 US$m Net amount 2020 US$m Net amount 2019 US$m Net amount 2018 US$m Underlying earnings 18,282 (5,195) (639) 12,448 10,373 8,808 Items excluded from underlying earnings Impairment charges (note 6) (1,243) 128 — (1,115) (1,658) (104) Net (losses)/gains on consolidation and disposal of interests in businesses (a) — — — — (291) 3,996 Exchange and derivative gains/(losses): – Exchange (losses)/gains on external net debt, intragroup balances and derivatives (b) (1,138) 5 8 (1,125) 51 550 – Losses on currency and interest rate derivatives not qualifying for hedge accounting (c) (142) (19) 4 (157) (59) (48) – Gains/(losses) on embedded commodity derivatives not qualifying for hedge accounting (d) 33 (10) (5) 18 (192) 202 Net losses from movements to closure estimates (non-operating and fully impaired sites) (e) (401) 100 1 (300) — (335) Gain relating to surplus land at Kitimat (f) — — — — — 569 Other exclusions (g) — — — — (214) — Total excluded from underlying earnings (2,891) 204 8 (2,679) (2,363) 4,830 Net earnings 15,391 (4,991) (631) 9,769 8,010 13,638 (a) In 2019, the net loss mainly related to the disposal of our entire 68.62% stake in Rössing Uranium on 16 July 2019 for which we recorded a pre-tax loss of US$289 million (US$289 million net of tax). In 2018, the net gain related mainly to the sales of the Hail Creek coal mine and the Kestrel underground coal mine, which both completed on 1 August 2018, the sale of the Dunkerque aluminium smelter on 14 December 2018 and the sale of Grasberg on 21 December 2018. The net gain in 2018 also includes a gain on consolidation recognised on the formation on 10 May 2018 of ELYSIS, a new joint venture to develop a carbon-free smelting process. Refer to note 36 f or further details in respect of these transactions. (b) Exchange losses on external net debt and intragroup balanc es comprise post-tax foreign exchange losses on intragroup balances of US$1,330 million partially offset by post-tax gains of US$205 million on external net debt, primarily as a result of strengthening of the Australian dollar against the US dollar. In 2019, exchange gains on external net debt and intragroup balances comprise post-tax foreign exchange gains on net debt of US$60 million and post-tax losses of US$9 million on intragroup balances, primarily as a result of the Canadian dollar strengthening against the US dollar. From 1 January 2019, all foreign exchange gains and losses relating to net debt are excluded fro m underlying earnings. In 2018 and previous years, foreign exchange gains and losses on non-US dollar cash held in US dollar functional currency entities was included within underlying earnings. The impact of this change on the reported 2018 comparatives is insignificant, and therefore the comparatives have not been restated. In 2018 the net exchange gains comprise post-tax foreign exchange losses of US$386 million on US dollar denominated net debt and US$936 million gains on intragroup balances. (c) Valuation changes on currency and interest rate derivatives, which are ineligible for hedge accounting, other than those embedded in commercial contracts, and the currency revaluation of embedded US dollar derivatives contained in contracts held by entities whose functional currency is not the US dollar. (d) Valuation changes on derivatives, embedded in commercial contracts, that are ineligible for hedge accounting, but for which there will be an offsetting change in future Group earnings. Mark-to-market movements on commodity derivatives entered into with the commercial objective of achieving spot pricing for the underlying transaction at the date of settlement are included in underlying earnings. (e) I n 2020 the pre-feasibility study for the Gove refinery closure was completed, resulting in an increase to the closure provision. As a non-operating asset, this increase was recognised through the income statement. Also in 2020, the feasibility study for the Argyle mine closure was completed, resulting in a decrease to the closure provision. As the assets at Argyle had previously been fully impaired this decrease was recognised through the income statement, in line with previous movements to the closure provision. This amount also includes an increase in Diavik's closure provision to reflect the latest findings from the ongoing Pre-Feasibility Study, recognised through the incomes statement as Diavik was fully impaired during the year. It also includes the net earnings impact ( US$138 million loss) in respect of increases to these closure provisions following a reduction to the closure discount rate to 1.5% . In 2018, the pre-feasibility study for the Argyle mine closure was completed, resulting in an increase to the closure provision. As the assets at Argyle had previously been fully impaired, this increase was not capitalised and was instead recognised in the income statement. Also in 2018, the feasibility study for the closure of the Ranger Project Area at Energy Resources of Australia (ERA) was finalised, resulting in an increase to the closure provision. As the assets of ERA had been fully impaired, this increase was recognised in the income statement. The charge was excluded from underlying earnings. (f) In November 2018, Rio Tinto completed the lease and sale of a wharf and land in Kitimat. The resulting gain on disposal of property, plant and equipment and other income were both excluded from underlying earnings on the grounds of materiality.

Operating segments - additional

Operating segments - additional information	12 Months Ended
	Dec. 31, 2020
Disclosure of operating segments [abstract]
Operating segments - additional information	3 Operating segments – additional information Consolidated sales revenue by destination (a) 2020 % 2020 US$m China 58.1 51.3 44.6 25,940 22,135 18,061 Asia (excluding China and Japan) 10.2 10.6 11.5 4,536 4,558 4,665 United States of America 10.9 14.2 15.6 4,867 6,125 6,337 Japan 7.5 8.9 9.6 3,354 3,855 3,873 Europe (excluding UK) 5.9 6.0 9.3 2,623 2,610 3,788 Canada 2.9 3.3 3.3 1,289 1,478 1,330 Australia 1.7 1.7 1.8 745 737 720 UK 0.5 0.6 0.7 242 248 264 Other countries 2.3 3.4 3.6 1,015 1,419 1,484 Consolidated sales revenue 100 100 100 44,611 43,165 40,522 (a) Consolidated sales revenue by geographical destination is based on the ultimate country of destination of the product, if known. If the eventual destination of the product sold through traders is not known then revenue is allocated to the location of the product at the time when control is transferred. Rio Tinto is domiciled in both the UK and Australia. Consolidated sales revenue by product Consolidated sales revenues of the Group are derived from the following products sold to external customers: Revenue from contracts with customers 2020 US$m Other revenue (a) 2020 US$m Consolidated sales revenue 2020 US$m Iron ore 28,202 1,000 29,202 Aluminium, Alumina and Bauxite 9,092 54 9,146 Copper 1,721 64 1,785 Industrial minerals 2,054 (3) 2,051 Gold 471 6 477 Diamonds 459 — 459 Uranium (b) 299 — 299 Other (b) 1,194 (2) 1,192 Consolidated sales revenue 43,492 1,119 44,611 Share of equity accounted unit sales and intra-subsidiary/equity accounted unit sales 2,407 Gross product sales 47,018 Revenue from contracts Other revenue (a) 2019 US$m Consolidated sales revenue Other revenue (a) 2018 US$m Iron ore 25,516 229 25,745 19,888 (21) 19,867 Aluminium, Alumina and Bauxite 10,207 (32) 10,175 12,041 (22) 12,019 Copper 2,030 (7) 2,023 2,420 (32) 2,388 Coal — — — 986 3 989 Industrial minerals 2,251 (12) 2,239 2,168 — 2,168 Gold 667 2 669 869 — 869 Diamonds 619 — 619 695 — 695 Uranium (b) 375 — 375 415 — 415 Other (b) 1,322 (2) 1,320 1,112 — 1,112 Consolidated sales revenue 42,987 178 43,165 40,594 (72) 40,522 Share of equity accounted unit sales and intra-subsidiary/equity accounted unit sales 2,202 2,313 Gross product sales 45,367 42,835 (a) Certain of the Group's products may be provisionally priced at the date revenue is recognised. The change in value of the provisionally priced receivables is based on relevant forward market prices and is included in “Other revenue” above. (b) Uranium sales revenues were previously included within "Other". These sales revenues are now presented separately and the 2018 and 2019 comparatives have been adjusted to ensure comparability. Non-current assets other than excluded items (a) The total of non-current assets other than excluded items is shown by location below. 2020 US$m 2019 US$m Australia 32,290 27,944 Canada 14,666 14,644 Mongolia 10,285 9,187 United States of America 6,090 5,459 Africa 3,294 3,583 South America 2,718 2,652 Europe (excluding France and the UK) 157 193 UK 117 158 France 55 64 Other countries 1,008 1,314 Total non-current assets other than excluded items 70,680 65,198 Non-current assets excluded from analysis above: Deferred tax assets 3,385 3,102 Other financial assets (b) 829 635 Quasi equity loans to equity accounted units (b) 112 113 Tax recoverable 4 5 Receivables and other assets 1,525 1,446 Total non-current assets per balance sheet 76,535 70,499 (a) Allocation of non-current assets by country is based on the location of the business units holding the assets. It includes investments in equity accounted units totalling US$3,652 million (2019: US$3,858 million) which represents the Group’s share of net assets excluding quasi equity loans shown separately above. (b) Loans to equity accounted units comprise quasi equity loans of US$112 million (2019: US$113 million) included in “Investments in equity accounted units” on the face of the balance sheet and non-current non-quasi equity loans of US$1 million (2019: US$39 million) shown within “Other financial assets”.

Net operating costs (excluding

Net operating costs (excluding items shown separately)	12 Months Ended
	Dec. 31, 2020
Net Operating Costs Excluding Items Shown Separately [Abstract]
Net operating costs (excluding items shown separately)	4 Net operating costs (excluding items shown separately) Note 2020 US$m 2019 US$m 2018 US$m Raw materials, consumables, repairs and maintenance 8,490 9,485 10,613 Amortisation of intangible assets 13 161 133 133 Depreciation of property, plant and equipment 14 4,118 4,251 3,882 Employment costs 5 4,770 4,522 4,728 Shipping and other freight costs (a) 2,088 2,257 2,580 (Increase)/decrease in finished goods and work in progress (47) 42 (186) Royalties 2,763 2,501 2,117 Amounts charged by equity accounted units (b) 958 1,136 1,200 Net foreign exchange losses/(gains) 300 (52) (56) Other external costs (a) 3,083 3,627 3,184 Loss/(gain) on sale of property, plant and equipment (c) 50 31 (506) Provisions (including exchange differences on provisions) 25 894 753 1,011 Research and development 45 45 45 Costs included above capitalised or shown separately as exploration and evaluation costs (d) (708) (651) (589) Other operating income (711) (773) (1,041) Net operating costs (excluding items shown separately) 26,254 27,307 27,115 (a) In 2020, other external costs include US$314 million (2019: US$327 million) of short-term lease costs and US$30 million (2019: US$15 million) of variable lease costs recognised in the income statement in accordance with IFRS 16 “Leases”. Refer to note 22. In 2018, net operating costs included US$787 million of operating lease expenses under IAS 17 “Leases”. Costs for leases of dry bulk vessels (which included costs for crewing services) were included within “Shipping and other freight costs” and other lease costs were included within “Other external costs”. (b) Amounts charged by equity accounted units relate to toll processing and also include purchases from equity accounted units of bauxite and aluminium which are then processed by the product group or sold to third parties. Generally, purchases are in proportion to the Group’s share of the equity accounted unit but in 2020, US$129 million (2019: US$291 million; 2018: US$332 million) related to purchases of the other investors’ share of production. (c) In 2018, includes a US$549 million pre-tax gain on the sale of property, plant and equipment at Kitimat. Refer to note 2.

Employment costs

Employment costs	12 Months Ended
	Dec. 31, 2020
Disclosure Of Employee Cost Explanatory [Abstract]
Employment costs	5 Employment costs Note 2020 US$m 2019 US$m 2018 US$m Total employment costs – Wages and salaries 4,141 3,923 4,154 – Social security costs 330 328 336 – Net post-retirement charge 42 469 384 532 – Share-based payment charge 41 138 123 122 5,078 4,758 5,144 Less: charged within provisions (a) 25 (308) (236) (416) Total employment costs 4 4,770 4,522 4,728 (a) Amounts included above relate to provisions for pensions, post-retirement healthcare, long service leave and other employee entitlements. These are included in “Provisions (including exchange differences on provisions)” in note 4.

Impairment charges

Impairment charges	12 Months Ended
	Dec. 31, 2020
Disclosure of impairment loss and reversal of impairment loss [abstract]
Impairment charges	6 Impairment charges Note Pre-tax amount 2020 US$m Taxation 2020 US$m Non-controlling interest 2020 US$m Net amount 2020 US$m Pre-tax amount 2019 US$m Pre-tax amount 2018 US$m Aluminium – Pacific Aluminium (489) 17 — (472) — Aluminium – Sohar (220) — — (220) — — Aluminium – ISAL (93) (38) — (131) (109) (123) Copper & Diamonds – Diavik (441) 149 — (292) — Copper & Diamonds – Oyu Tolgoi — — — — (2,240) — Aluminium - Yarwun alumina refinery — — — — (1,138) — Energy & Minerals – Rössing — — — — — (9) Total impairment charge (1,243) 128 — (1,115) (3,487) (132) Allocated as: Intangible assets 13 (4) (1) (2) Property, plant and equipment 14 (900) (3,486) (130) Investment in equity accounted units ("EAUs") (339) — — Total impairment charge (1,243) (3,487) (132) Comprising: Impairment charges of consolidated balances (904) (3,487) (132) Impairment charges related to EAUs (pre-tax) (368) — — Total impairment charge (1,272) (3,487) (132) Taxation (including related to EAUs) 157 323 25 Non-controlling interests — 1,506 3 Total impairment in the income statement (1,115) (1,658) (104) Aluminium – Pacific Aluminium, Australia and New Zealand On 9 July 2020, we announced the conclusion of the NZAS strategic review and gave Meridian Energy 14 months' notice for the termination of the power contract. As a result of the decision to wind-down operations an impairment trigger was identified. The net present value of post-tax cash flows over the remaining life for this cash-generating unit (CGU) was negative and therefore the non-current assets of the smelter were fully impaired. On 14 January 2021 a new agreement was reached with Meridian Energy in relation to power prices, allowing NZAS to continue operating the Tiwai Point aluminium smelter until December 2024. The extension allows time for detailed closure studies to be completed and for NZAS to support the government and Southland community in planning for the future. We have evaluated and concluded that these updated circumstances are not a trigger for impairment reversal. The high operating costs and challenging outlook for the aluminium industry have also resulted in impairment triggers being identified at the Bell Bay aluminium smelter in Tasmania, Australia and at Boyne Smelter in Queensland, Australia at 30 June 2020. Bell Bay has a power contract to 2025 with Hydro Tasmania and with the current market context the forecast net present value of cash flows over that period was negative. The property, plant and equipment of the Bell Bay smelter was therefore fully impaired. We determined the recoverable amount for our share of the Boyne Smelter CGU which also includes the Gladstone Power Station as US$273 million based on post-tax cash flows expressed in real terms and discounted at 6.6%. Accordingly our share of impairment after tax in the equity accounted unit was US$119 million (US$148 million pre-tax) related to the smelter and US$26 million (US$36 million pre-tax) related to the power station. Aluminium – Sohar In 2020, the challenging outlook for the Middle Eastern aluminium industry was identified as an impairment trigger at the Sohar aluminium smelter in Oman, an equity accounted unit of the Group. At 30 September 2020 we determined the recoverable amount for our share of the Sohar CGU to be US$258 million based on post-tax cash flows expressed in real terms and discounted at 7.6%. Accordingly our share of impairment after tax in the equity accounted unit was US$220 million. 6 Impairment charges continued Aluminium – ISAL smelter, Iceland In 2018, we reached agreement with Hydro to sell the ISAL smelter in Iceland, our 53.3% interest in the Aluchemie anode plant in the Netherlands and our 50% share in the Aluminium fluoride plant in Sweden (ISAL). The anticipated headline sales price of US$345 million was lower than the carrying value of these assets, leading us to recognise an impairment charge of US$123 million. This was based on a fair value less cost of disposal (FVLCD) model, against property, plant and equipment and acquired software. Subsequently, Hydro withdrew its offer. In 2019, these assets no longer met the accounting criteria to be classified as assets held for sale. Accordingly these non-current assets were tested for impairment. We calculated the recoverable amount for the CGUs based on the IAS 36 value-in-use methodology by reference to the net present value of post-tax cash flows expressed in real terms and discounted at 6.9%. These were US$302 million for the CGU comprising ISAL and Aluchemie and US$46 million for Alufluor. This resulted in a pre-tax impairment charge of US$109 million allocated to property, plant and equipment and intangibles in the ISAL a nd Aluchemie CGU. In February 2020 we announced a strategic review of the ISAL smelter in Iceland and the challenging market conditions were identified as an impairment trigger. The net present value of cash flows projected over the remaining life for this CGU did not support retaining any carrying value for the non-current assets of the CGU, which were fully impaired following a pre-tax impairment charge of US$204 million in the first half of 2020. During subsequent negotiations Landsvirkjun tabled an improved offer for power delivery, restoring the competitiveness of the smelter over its remaining life. We have concluded these updated circumstances, represent an indicator of partial impairment reversal. When combined with improved pricing since the half year we have calculated a recoverable amount of US$139 million based on the IAS 36 fair value less cost of disposal (FVLCD) methodology, discounted using a post-tax discount rate of 6.6% expressed in real terms. As a result we have reversed previously recorded pre-tax impairment of US$111 million reflected as an adjustment to the impairment charge recognised in the first half of 2020. Copper & Diamonds – Diavik, Canada The COVID-19 pandemic has significantly disrupted the global demand for diamonds with many countries restricting the movement of citizens and closing retail outlets. Our 40% joint venture partner at the Diavik diamond mine filed for creditor protection in April 2020 and has since defaulted on its cash calls. Together these circumstances were identified as an impairment trigger. The net present value of post-tax cash flows projected over the remaining life of the Diavik diamond mine to 2025 did not support retaining any carrying value for the property, plant and equipment and intangible assets of the CGU, which have therefore been fully impaired. Copper & Diamonds – Oyu Tolgoi, Mongolia On 16 July 2019 we announced that the first sustainable production from the Oyu Tolgoi underground project could be delayed by 16 to 30 months compared with the original feasibility study guidance in 2016. We also announced that development capital spend for the project may increase by between US$1.2 billion and US$1.9 billion in excess of the US$5.3 billion previously disclosed. We identified these matters as an impairment trigger and prepared an assessment of the recoverable amount for the CGU at 30 June 2019 using a FVLCD model, as prescribed by IAS 36 “Impairment of Assets”. In arriving at a recoverable amount, as at 30 June 2019, we estimated post-tax cash flows expressed in real terms over the current life of mine plus anticipated future expansions, utilising mineral resources. The mineral resources incorporate almost two billion tonnes of ore, which contributes approximately 20% to the total recoverable amount. We discounted the cash flows using a post-tax discount rate of 8.3% expressed in real terms. Due to the inputs used, the recoverable amount of the Oyu Tolgoi CGU was classified as level 3 under the fair value hierarchy. At 30 June 2019 we determined the recoverable amount to be US$8.3 billion on a post-tax basis which resulted in a pre-tax impairment charge of US$2.2 billion (100% basis). This was allocated to mining properties and the underground development assets under construction. The net adjustment to tax represented an increase to deferred tax assets of US$320 million for the temporary difference corresponding to the impairment and a decrease in deferred tax assets of US$359 million for tax losses that were expected to expire without utilisation. Since June 2019, the carrying value of Oyu Tolgoi on the same basis has increased to US$10.1 billion (100% basis), mainly due to capital expenditure completed in the interim. The execution of this capital expenditure also results in a corresponding increase in the value of the asset over this period. Prior to completion of the underground project, the net present value of cash flows also increases by approximately US$1.1 billion per annum due to unwinding of the discount for the time value of money. Such valuation increases are not indicative of impairment reversal. On 16 December 2020 we confirmed the completion of the Definitive Estimate and selection of a preferred development option for the Oyu Tolgoi underground project. Development capital assumptions of US$6.75 billion and forecast sustainable production by October 2022 incorporate the impacts of COVID-19. The latest information is within the range of assumptions used to calculate the CGU's recoverable amount in the most recent impairment test, described above, and is not indicative of an impairment loss. The next major milestone for the project development is the undercut, scheduled for mid-2021, which initiates the caving process. Study work also continues on the Panel 1 and Panel 2 sections of the underground, with initial recommendations expected mid-2021. These studies will also consider options and associated costs to recover the copper and gold contained within the pillars added to the mine design of Panel 0. On 4 January 2021, the Government of Mongolia advised Rio Tinto that they were dissatisfied with the results of the Definitive Estimate and the funding implications for the sharing of economic benefits between the shareholders of Oyu Tolgoi LLC. The Government has also stressed the importance of achieving a comprehensive solution which addresses the social issues of importance to Mongolia, such as water usage and the tax matters which have been referred to International Arbitration. We are engaging with the Government in relation to the definitive estimate and are in active discussions with them to address and close all outstanding issues and increase the project's benefit to all stakeholders. Should future negotiations with the Government of Mongolia result in changes to the operating cash profile of the assets, an impairment test may be necessary. The funding of equity contributions to the project have been accounted for in accordance with the accounting policy in note 1 (xii) and additional information regarding the lending certificates and non-controlling interests are provided in note 32. Aluminium – Yarwun alumina refinery In 2019, our annual impairment assessment of the Yarwun CGU resulted in a pre-tax impairment charge of US$1,138 million to property, plant and equipment as a result of this CGU being assessed on a stand-alone basis for the first time and a 30% year-on-year reduction in the spot price of alumina to US$275/t at 31 December 2019. In 2020, we continued to monitor the Yarwun CGU closely for additional indicators of impairment given the limited headroom as a consequence of previous impairment, together with the sensitivity of the valuation to movements in the alumina price and headwinds faced by the aluminium sector since the onset of the COVID-19 pandemic. We have considered the impact of recent volatility in the alumina spot price through 2020, noting its recovery from a low of US$226/t in June 2020 to over US$300/t by the end of the year, as well as valuation upside attributable to a reduction in input costs over the period under review. No impairment triggers have been identified in 2020 and the carrying value remains supportable.

Share of profit after tax of eq

Share of profit after tax of equity accounted units	12 Months Ended
	Dec. 31, 2020
Share of profit (loss) of associates and joint ventures accounted for using equity method [abstract]
Share of profit after tax of equity accounted units	7 Share of profit after tax of equity accounted units 2020 US$m 2019 US$m 2018 US$m Sales revenue: Rio Tinto share (a) 2,490 2,358 2,497 Operating costs (1,439) (1,812) (1,656) Profit before finance items and taxation 1,051 546 841 Finance items (59) (65) (69) Share of profit after tax of equity accounted units 23 10 14 Profit before taxation 1,015 491 786 Taxation (363) (190) (273) Profit for the year (Rio Tinto share) 652 301 513 (a) Sales revenue of equity accounted units includes sales by equity accounted units to Group subsidiaries.

Finance income and finance cost

Finance income and finance costs	12 Months Ended
	Dec. 31, 2020
Disclosure Of Finance Income And Finance Costs [Abstract]
Finance income and finance costs	8 Finance income and finance costs Note 2020 US$m 2019 US$m 2018 US$m Finance income from equity accounted units 4 4 7 Other finance income (including bank deposits, net investment in leases, and other financial assets) 137 296 242 Total finance income 141 300 249 Interest on: – Financial liabilities at amortised cost (excluding lease liabilities) and associated derivatives (561) (816) (775) – Lease liabilities (50) (55) (2) Fair value movements: – Bonds designated as hedged items in fair value hedges (284) (185) 96 – Derivatives designated as hedging instruments in fair value hedges 287 181 (73) Loss on early redemption of bonds (a) — — (94) Amounts capitalised 14 340 321 296 Total finance costs (268) (554) (552) (a) In 2018 we completed a bond buy-back programme of US$1.9 billion (nominal value). Loss on early redemption of bonds included a premium charge of US$72 million, unamortised debt issuance costs and fees of US$9 million, the write-off of the fair value hedge adjustment of US$16 million and the reclassification of a gain out of the cost of hedging reserve of US$3 million. Net interest paid in the Group cash flow statement included the payment of the premiums and the accelerated interest associated with the bond redemptions (US$80 million). There was no bond buy-back programme in 2020 or 2019.

Taxation

Taxation	12 Months Ended
	Dec. 31, 2020
Disclosure Of Income Tax [Abstract]
Taxation	9 Taxation Taxation charge Note 2020 US$m 2019 US$m 2018 US$m – Current 5,169 4,436 3,726 – Deferred 17 (178) (289) 516 Total taxation charge 4,991 4,147 4,242 Prima facie tax reconciliation 2020 US$m 2019 US$m 2018 US$m Profit before taxation 15,391 11,119 18,167 Deduct: share of profit after tax of equity accounted units (a) (652) (301) (513) Add: impairment after tax of investments in equity accounted units (a) 339 — — Parent companies' and subsidiaries' profit before tax 15,078 10,818 17,654 Prima facie tax payable at UK rate of 19% (2019: 19%; 2018: 19%) 2,865 2,055 3,354 Higher rate of taxation on Australian underlying earnings 1,779 1,495 1,106 Impact of items excluded in arriving at underlying earnings (b) : – Impairment charges (c) 44 340 — – Net gains and losses on consolidation and disposal of interests in businesses — 55 (251) – Exchange and gains/losses on derivatives 260 (22) 32 – Losses from increases to closure estimates (non-operating and fully impaired sites) (24) — 30 – Gain relating to surplus land at Kitimat — — (81) – Other exclusions — 38 — Impact of changes in tax rates and laws — 1 47 Other tax rates applicable outside the UK and Australia on underlying earnings (80) (110) (47) Resource depletion and other depreciation allowances (34) (57) (46) Recognition of previously unrecognised deferred tax assets (d) (182) — — Write-down of previously recognised deferred tax assets (e) 173 42 13 Amounts under/(over) provided in prior years 9 83 (108) Other items (f) 181 227 193 Total taxation charge (a) 4,991 4,147 4,242 (a) This tax reconciliation relates to the Group's parent companies, subsidiaries and joint operations, and excludes equity accounted units. The Group's share of profit of equity accounted units is net of tax charges of US$363 million (2019: US$190 million; 2018: US$273 million). Impairment after tax of investments in equity accounted units is net of tax credits of US$29 million (2019: US$nil; 2018: US$nil). (b) The impact for each item includes the effect of tax rates applicable outside the UK. (c) The tax impact of impairments includes the write-down of deferred tax assets at ISAL and NZAS and non-recognition of deferred tax on those impairments. The tax impact also includes recognition at local tax rates of deferred tax assets arising on the impairments of Bell Bay, Gladstone Power Station and Diavik. In the comparative period to 31 December 2019, the tax impact of impairment includes the write down of deferred tax assets in respect of prior year tax losses in Mongolia and recognition of deferred tax on impaired assets. Refer to note 6. (d) The recognition of previously unrecognised deferred tax assets relates to the recognition of prior year deferred tax assets on losses and on impaired assets at Oyu Tolgoi due to improved deferred tax asset recovery expectations. (e) Write down of previously recognised deferred tax assets relates primarily to the partial de-recognition of deferred tax assets in our Australian Aluminium business. (f) Other items include non-deductible costs and withholding taxes, and various adjustments to provisions for taxation, the most significant of which relate to transfer pricing matters, including issues under discussion with the Australian Tax Office. 2020 US$m 2019 US$m 2018 US$m Tax on fair value movements: – Cash flow hedge fair value gains 3 (6) (54) Tax credit/(charge) on actuarial gains and losses on post-retirement benefit plans 112 83 (271) Tax relating to components of other comprehensive income/(loss) for the year (a) 115 77 (325) (a) This comprises a deferred tax credit of US$115 million (2019: credit of US$77 million; 2018: charge of US$325 million) and a current tax charge of US$nil (2019: US$nil; 2018: US$nil), see note 17.

Earnings per ordinary share

Earnings per ordinary share	12 Months Ended
	Dec. 31, 2020
Earnings per share [abstract]
Earnings per ordinary share	10 Earnings per ordinary share 2020 Earnings US$m 2020 Weighted average number of shares (millions) 2020 Per share amount (cents) 2019 Earnings US$m 2019 Weighted average number of shares (millions) 2019 Per share amount (cents) Basic earnings per share attributable to ordinary shareholders of Rio Tinto (a) 9,769 1,617.4 604.0 8,010 1,630.1 491.4 Diluted earnings per share attributable to ordinary shareholders of Rio Tinto (b) 9,769 1,628.6 599.8 8,010 1,642.1 487.8 2018 Earnings US$m 2018 Weighted average number of shares (millions) 2018 Per share amount (cents) Basic earnings per share attributable to ordinary shareholders of Rio Tinto (a) 13,638 1,719.3 793.2 Diluted earnings per share attributable to ordinary shareholders of Rio Tinto (b) 13,638 1,731.7 787.6 (a) The weighted average number of shares is calculated as the average num ber of Rio Tinto plc shares outstanding not held as treasury shares of 1,246.5 million ( 2019 : 1,259.4 million ; 2018 : 1,312.7 million ) plus the average number of Rio Tinto Limited shares outstanding of 370.9 million ( 2019 : 370.7 million ; 2018 : 406.6 million ) over the relevant period. There were no cross holdings of shares between Rio Tinto Limited and Rio Tinto plc at 31 December 2020 ( 31 December 2019 : nil ). (b) For the purposes of calculating diluted earnings per share, the effect of dilutive securities of 11.2 million s hares in 2020 (2019: 12.0 million; 2018: 12.4 million) is added to the weighted average number of shares described in (a) above. This effect is calculated under the treasury stock method, in accordance with IAS 33 “Earnings per Share”. The Group’s only potential dilutive ordinary shares are share options for which terms and conditions are described in note 41.

Dividends

Dividends	12 Months Ended
	Dec. 31, 2020
Disclosure Of Dividends [Abstract]
Dividends	11 Dividends 2020 US$m 2019 US$m 2018 US$m Rio Tinto plc previous year final dividend paid 2,783 2,245 2,446 Rio Tinto plc previous year special dividend paid — 3,032 — Rio Tinto plc interim dividend paid 1,937 1,930 1,666 Rio Tinto plc interim special dividend paid — 780 — Rio Tinto Limited previous year final dividend paid 857 666 731 Rio Tinto Limited previous year special dividend paid — 900 — Rio Tinto Limited interim dividend paid 555 556 513 Rio Tinto Limited interim special dividend paid — 225 — Dividends paid during the year 6,132 10,334 5,356 Dividends per share: paid during the year 386.0 c 635.0 c 307.0 c Final dividends per share: proposed in the announcement of the results for the year 309.0 c 231.0 c 180.0 c Special dividends per share: proposed in the announcement of the results for the year 93.0 c — 243.0 c Dividends per share 2020 Dividends per share 2019 Dividends per share 2018 Rio Tinto plc previous year final (pence) 177.47 p 135.96 p 129.43 p Rio Tinto plc previous year special (pence) — 183.55 p — Rio Tinto plc interim (pence) 119.74 p 123.32 p 96.82 p Rio Tinto plc interim special (pence) — 49.82 p — Rio Tinto Limited previous year final – fully franked at 30% (Australian cents) 349.74 c 250.89 c 228.53 c Rio Tinto Limited previous year special – fully franked at 30% (Australian cents) — 338.70 c — Rio Tinto Limited interim – fully franked at 30% (Australian cents) 216.47 c 219.08 c 170.84 c Rio Tinto Limited interim special – fully franked at 30% (Australian cents) — 88.50 c — Number of shares 2020 (millions) Number of shares 2019 (millions) Number of shares 2018 (millions) Rio Tinto plc previous year final 1,246.4 1,265.0 1,334.8 Rio Tinto plc previous year special N/A 1,265.0 N/A Rio Tinto plc interim 1,246.5 1,256.4 1,308.4 Rio Tinto plc interim special N/A 1,256.4 N/A Rio Tinto Limited previous year final 371.2 371.2 412.4 Rio Tinto Limited previous year special N/A 371.2 N/A Rio Tinto Limited interim 371.2 371.2 412.4 Rio Tinto Limited interim special N/A 371.2 N/A 11 Dividends continued The dividends paid in 2020 are based on the following US cents per share amounts: 2019 final – 231.0 cents, 2020 interim – 155.0 cents (2019 dividends paid: 2018 final – 180.0 cents, 2018 final special – 243.0 cents , 2019 interim – 151.0 cents; 2019 interim special – 61.0 cents, 2018 dividends paid: 2017 final – 180.0 cents, 2018 interim – 127.0 cents). The number of shares on which Rio Tinto plc dividends are based excludes those held as treasury shares and those held by employee share trusts which waived the right to dividends. Employee share trusts waived dividends on 258,779 Rio Tinto plc ordinary shares and 28,743 American Depository Receipts (ADRs) for the 2019 final dividend and on 171,213 Rio Tinto plc ordinary shares and 29,634 ADRs for the 2020 interim dividend (2019: on 852,283 Rio Tinto plc ordinary shares and 37,678 ADRs for the 2018 final dividend and on 564,099 Rio Tinto plc ordinary shares and 47,674 ADRs for the 2019 interim dividend; 2018: on 132,294 Rio Tinto plc ordinary shares and 22,824 ADRs for the 2017 final dividend and on 314,529 Rio Tinto plc ordinary shares and 36,321 ADRs for the 2018 interim dividend). In 2020, 2019 and 2018, no Rio Tinto Limited shares were held by Rio Tinto plc. The number of shares on which Rio Tinto Limited dividends are based excludes those held by shareholders who have waived the rights to dividends. Employee share trusts waived dividends on 98,065 Rio Tinto Limited ordinary shares for the 2019 final dividend and on 84,377 shares for the 2020 interim dividend (2019: on 628,566 shares for the 2018 final dividend and 342,062 shares for the 2019 interim dividend; 2018: on 130,129 shares for the 2017 final dividend and 251,394 shares for the 2018 interim dividend). In addition, the directors of Rio Tinto announced a final dividend of 309.0 cents per share and a special dividend of 93.0 cents per share on 17 February 2021. This is expected to result in payments of US$6.5 billion. The dividend will be paid o n 15 April 2021 t o Rio Tinto plc and Rio Tinto Limited shareholders on the register at the close of business o n 5 March 2021. The proposed Rio Tinto Limited dividends will be franked out of existing franking credits or out of franking credits arising from the payment of income tax during 2021. The approximate amount of the Rio Tinto Limited consolidated tax group’s retained profits and reserves that could be distributed as dividends and franked out of available credits that arose from net payments of income tax in respect of periods up to 31 December 2020 (after deducting franking credits expected to be utilised on the 2020 final and special dividends declared) is US$11,014 million (2019: US$8,599 million; 2018: US$6,178 million ).

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2020
Goodwill [Abstract]
Goodwill	12 Goodwill 2020 US$m 2019 US$m Net book value At 1 January 922 912 Adjustment on currency translation 24 10 At 31 December 946 922 – cost 17,341 16,926 – accumulated impairment (16,395) (16,004) At 1 January – cost 16,926 15,861 – accumulated impairment (16,004) (14,949) At 31 December, goodwill has been allocated as follows: 2020 US$m 2019 US$m Net book value Richards Bay Minerals 468 487 Pilbara 383 349 Dampier Salt 95 86 946 922 12 Goodwill continued Impairment tests for goodwill Richards Bay Minerals Richards Bay Minerals’ annual impairment review resulted in no impairment charge for 2020 (2019: no impairment charge). The recoverable amount has been assessed by reference to fair value less cost of disposal (FVLCD), in line with the policy set out in note 1(i) and classified as level 3 under the fair value hierarchy. FVLCD was determined by estimating cash flows until the end of the life-of-mine plan including anticipated expansions. In arriving at FVLCD, a post-tax discount rate of 8.6% (2019: 8.6%) has been applied to the post-tax cash flows expressed in real terms. The key assumptions to which the calculation of FVLCD for Richards Bay Minerals is most sensitive and the corresponding decrease in FVLCD are set out below: US$m 5% decrease in the titanium slag price 182 1% increase in the discount rate applied to post-tax cash flows 213 10% strengthening of the South African rand 393 Other assumptions include the long-term pig iron and zircon prices and operating costs. Future selling prices and operating costs have been estimated in line with the policy set out in note 1(i). The recoverable amount of the cash-generating unit (CGU) exceeds the carrying value when each of these sensitivities are applied whilst keeping all other assumptions constant. Pilbara The annual impairment review of the Pilbara CGU has been assessed by reference to FVLCD using discounted cash flows, which is in line with the policy set out in note 1(i) and is classified as level 3 under the fair value hierarchy. In arriving at FVLCD, a post-tax discount rate of 6.6% (2019: 6.6%) has been applied to the post-tax cash flows expressed in real terms. The recoverable amount was determined to be significantly in excess of carrying value, and there are no reasonably possible changes in key assumptions that would cause the remaining goodwill to be impaired.

Intangible assets

Intangible assets	12 Months Ended
	Dec. 31, 2020
Intangible Assets [Abstract]
Intangible assets	13 Intangible assets Year ended 31 December 2020 Exploration and evaluation (a) US$m Trademarks, patented and Contract based intangible assets (b) US$m Other Total Net book value At 1 January 2020 173 44 1,947 473 2,637 Adjustment on currency translation 17 3 56 35 111 Expenditure during the year 87 — — 69 156 Amortisation for the year (c) — (14) (8) (139) (161) Impairment charges (d) — — — (4) (4) Disposals, transfers and other movements (6) — (1) 23 16 At 31 December 2020 271 33 1,994 457 2,755 – cost 2,415 232 3,070 1,710 7,427 – accumulated amortisation and impairment (2,144) (199) (1,076) (1,253) (4,672) Year ended 31 December 2019 Exploration and evaluation (a) US$m Trademarks, patented and Contract based intangible assets (b) US$m Other Total Net book value At 1 January 2019 233 59 1,982 505 2,779 Adjustment on currency translation (1) (1) 74 (1) 71 Expenditure during the year 57 — — 34 91 Amortisation for the year (c) — (14) (8) (111) (133) Impairment charges (d) — — — (1) (1) Disposals, transfers and other movements (e) (116) — (101) 47 (170) At 31 December 2019 173 44 1,947 473 2,637 – cost 2,306 214 3,002 1,516 7,038 – accumulated amortisation and impairment (2,133) (170) (1,055) (1,043) (4,401) 13 Intangible assets continued (a) Exploration and evaluation assets’ useful lives are not determined until transferred to property, plant and equipment. (b) The Group benefits from certain intangible assets acquired with Alcan, including power supply contracts, customer contracts and water rights. The water rights are expected to contribute to the efficiency and cost effectiveness of operations for the foreseeable future; accordingly, these rights are considered to have indefinite lives and are not subject to amortisation but are tested annually for impairment. These water rights constitute the majority of the amounts in “Contract based intangible assets”. The remaining carrying value of the water rights of US$1,798 million as at 31 December 2020 (31 December 2019: US$1,759 million) relates wholly to the Quebec smelters cash-generating unit (CGU). The Quebec smelters CGU was tested for impairment by reference to fair value less cost of disposal (FVLCD) using discounted cash flows, which is in line with the policy set out in note 1(i). The recoverable amount of the Quebec smelters is classified as level 3 under the fair value hierarchy. In arriving at FVLCD, post-tax cash flows expressed in real terms have been estimated over the expected useful economic lives of the underlying smelting assets and discounted using a real post-tax discount rate of 6.6% (2019: 6.6%). T he recoverable amounts were determined to be significantly in excess of carrying value, and there are no reasonably possible changes in key assumptions that would cause the remaining water rights to be impaired. (c) Finite life intangible assets are amortised over their useful economic lives on a straight line or units of production basis, as appropriate. Where amortisation is calculated on a straight line basis, the following useful lives have been determined: Trademarks, patented and non-patented technology: Trademarks: 14 to 20 years Patented and non-patented technology: ten to 20 years Contract-based intangible assets: Power contracts/water rights: two to 45 years Other purchase and customer contracts: five to 15 years Other intangible assets: Internally generated intangible assets and computer software: two to five years Other intangible assets: two to 20 years (d) Impairment charges in 2020 relate to the Diavik diamond mine. Impairment charges in 2019 relate to the ISAL smelter. See note 6. (e) In 2019, disposals, transfers and other movements included the transfer from exploration and evaluation of the Zulti South project at Richards Bay Minerals to construction in progress following approval in April 2019 and reclassification of certain mineral rights from contract based intangibles to property, plant and equipment. Exploration and evaluation expenditure The charge for the year and the net amount of intangible assets capitalised during the year are as follows: 2020 US$m 2019 US$m 2018 US$m Net expenditure in the year (net of cash proceeds of US$1 million (2019: US$10 million; 2018: US$233 million) on disposal of undeveloped projects) (711) (671) (345) Non-cash movements and non-cash proceeds on disposal of undeveloped projects — — 45 Amount capitalised during the year 87 57 90 Net charge for the year (624) (614) (210) Reconciliation to income statement: Exploration and evaluation costs (625) (624) (488) Profit relating to interests in undeveloped projects (a) 1 10 278 Net charge for the year (624) (614) (210) (a) During 2018, profit relating to interests in undeveloped properties related to the gains on the sales of Valeria (US$83 million) and Winchester South (US$195 million) undeveloped properties which were included within underlying earnings. At 31 December 2020, a total of US$271 million has been capitalised related to projects which have not yet been approved to proceed (31 December 2019: US$173 million ).

Property, plant and equipment

Property, plant and equipment	12 Months Ended
	Dec. 31, 2020
Property, plant and equipment [abstract]
Property, plant and equipment	14 Property, plant and equipment Property, plant and equipment comprises owned and leased assets. 2020 US$m 2019 US$m Property, plant and equipment – owned 62,007 56,307 Right of use assets – leased 875 1,065 Net book value 62,882 57,372 14 Property, plant and equipment continued Property, plant and equipment – Owned Year ended 31 December 2020 Note Mining properties and leases (a) US$m Land and buildings US$m Plant Capital Total Net book value At 1 January 2020 10,402 6,403 31,491 8,011 56,307 Adjustment on currency translation (b) 457 307 1,758 366 2,888 Adjustments to capitalised closure costs 25 946 — — — 946 Interest capitalised (c) 8 — — — 340 340 Additions 329 45 726 5,211 6,311 Depreciation for the year (a)(d) (666) (354) (2,776) — (3,796) Impairment charges (e) (327) (85) (369) (82) (863) Disposals (2) (13) (64) (16) (95) Transfers and other movements (f) 34 66 1,988 (2,119) (31) At 31 December 2020 11,173 6,369 32,754 11,711 62,007 – cost 25,052 12,178 71,603 12,906 121,739 – accumulated depreciation and impairment (13,879) (5,809) (38,849) (1,195) (59,732) Non-current assets pledged as security (g) 1,712 494 5,065 6,974 14,245 Year ended 31 December 2019 Note Mining properties and leases (a) US$m Land and buildings US$m Plant Capital Total Net book value At 1 January 2019 11,063 6,263 32,019 7,016 56,361 Adjustment for transition to new accounting standard (h) — — (31) — (31) Restated opening balance 11,063 6,263 31,988 7,016 56,330 Adjustment on currency translation (b) 27 72 286 41 426 Adjustments to capitalised closure costs 25 840 — — — 840 Interest capitalised (c) 8 — — — 321 321 Additions 433 46 616 4,435 5,530 Depreciation for the year (a)(d) (729) (381) (2,869) — (3,979) Impairment charges (e) (1,339) (96) (1,115) (926) (3,476) Disposals — (9) (44) (19) (72) Transfers and other movements (f) 107 508 2,629 (2,857) 387 At 31 December 2019 10,402 6,403 31,491 8,011 56,307 – cost 24,875 11,517 66,705 9,188 112,285 – accumulated depreciation and impairment (14,473) (5,114) (35,214) (1,177) (55,978) Non-current assets pledged as security (g) 1,805 571 5,111 5,271 12,758 (a) At 31 December 2020, the net book value of capitalised production phase stripping costs totalled US$2,398 million, with US$2,019 million within "Property, plant and equipment" and a further US$379 million within "Investments in equity accounted units" (2019: total of US$2,276 million, with US$1,833 million in "Property, plant and equipment" and a further US$443 million within "Investments in equity accounted units"). During the year, capitalisation of US$380 million was partly offset by depreciation of US$267 million (including amounts recorded within equity accounted units). Depreciation of deferred stripping costs in respect of subsidiaries of US$145 million (2019: US$139 million; 2018: US$134 million) is included within “Depreciation for the year”. (b) Adjustment on currency translation represents the impact of exchange differences arising on the translation of the assets of entities with functional currencies other than the US dollar, recognised directly in the currency translation reserve. The adjustment in 2020 arose from the strengthening of the Australian dollar and Canadian dollar against the US dollar. (c) Interest is capitalised at a rate based on the Group or relevant subsidiary’s cost of borrowing or at the rate on project specific debt, where applicable. The Group’s average borrowing rate used for capitalisation of interest is 4.20% (2019: 5.30%). (d) Assets within operations for which production is not expected to fluctuate significantly from one year to another or which have a physical life shorter than the related mine are depreciated on a straight line basis as follows: Land and buildings: Land: not depreciated Buildings: five Plant and equipment: Other plant and equipment: three Power assets: 25 to 50 years Capital work in progress: not depreciated (e) During 2020, impairment charges relate to Pacific Aluminium smelters, the ISAL smelter in Iceland and our interest in the Diavik diamond mine (see note 6). During 2019, impairment charges primarily related to the Oyu Tolgoi underground project, Yarwun alumina refinery and the ISAL smelter (see note 6). (f) “Transfers and other movements” includes reclassifications between categories. In 2019, "Transfers and other movements" included ISAL assets held for sale as these assets no longer met the criteria to be classified as assets held for sale. (g) Excludes assets held under capitalised lease arrangements. Non-current assets pledged as security represent amounts pledged as collateral against US$4,518 million (2019: US$4,540 million) of loans, which are included in note 21. (h) The impact of the transition to new accounting standard IFRS 16 “Leases” on 1 January 2019. Right-of-use assets – Leased Land Plant Total Net book value 31 December 2020 475 400 875 31 December 2019 507 558 1,065 Additions for the year 31 December 2020 30 75 105 31 December 2019 89 212 301 Depreciation for the year (included within operating costs) 31 December 2020 (93) (229) (322) 31 December 2019 (69) (203) (272) Impairment charges (a) 31 December 2020 (6) (31) (37) 31 December 2019 (6) (4) (10) (a) Impairment charges in 2020 relate to Pacific Aluminium smelters, the ISAL smelter in Iceland and our interest in the Diavik diamond mine (see note 6). Impairment charges in 2019 related to the ISAL smelter (see note 6).

Investments in equity accounted

Investments in equity accounted units	12 Months Ended
	Dec. 31, 2020
Disclosure Of Investments Accounted For Using Equity Method Explanatory [Abstract]
Investments in equity accounted units	15 Investments in equity accounted units Summary balance sheet (Rio Tinto share) 2020 US$m 2019 US$m Rio Tinto's share of assets – Non-current assets 5,307 5,820 – Current assets 1,077 831 6,384 6,651 Rio Tinto's share of liabilities – Current liabilities (785) (675) – Non-current liabilities (1,835) (2,005) (2,620) (2,680) Rio Tinto's share of net assets 3,764 3,971 Further details of investments in equity accounted units are set out in notes 34 and 35. At 31 December 2020 and 2019, the Group had no investments in equity accounted units with shares listed on recognised stock exchanges.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2020
Disclosure Of Inventories [Abstract]
Inventories	16 Inventories 2020 US$m 2019 US$m Raw materials and purchased components 640 675 Consumable stores 1,050 925 Work in progress 1,288 1,066 Finished goods and goods for resale 1,113 936 Total inventories 4,091 3,602 Comprising: Expected to be used within one year 3,917 3,463 Expected to be used after more than one year 174 139 Total inventories 4,091 3,602 During 2020, the Group recognised a net inventory write back of US$15 million (2019: net inventory write down of US$42 million). This comprised inventory write-offs of US$35 million (2019: US$134 million) partly offset by write-back of previously written down inventory due to an increase in realisable values amounting to US$50 million (2019: US$92 million). At 31 December 2020, US$621 million (2019: US$611 million) of inventories were pledged as security for liabilities.

Deferred taxation

Deferred taxation	12 Months Ended
	Dec. 31, 2020
Deferred tax assets and liabilities [abstract]
Deferred taxation	17 Deferred taxation 2020 US$m 2019 US$m At 1 January – deferred tax liability (118) (532) Adjustment on currency translation (43) (77) Credited to the income statement 178 289 Credited to statement of comprehensive income (a) 115 77 Other movements (b) 14 125 At 31 December – deferred tax asset/(liability) 146 (118) Comprising: – deferred tax assets (c)(d) 3,385 3,102 – deferred tax liabilities (e) (3,239) (3,220) 17 Deferred taxation continued Deferred tax balances for which there is a right of offset within the same tax jurisdiction are presented net on the face of the balance sheet as permitted by IAS 12. The closing deferred tax assets and liabilities, prior to this offsetting of balances, are shown below. Analysis of deferred tax Total 2020 US$m Total 2019 US$m Deferred tax assets arising from: Tax losses (c) 1,867 1,847 Provisions 2,121 1,810 Capital allowances 529 604 Post-retirement benefits 698 599 Unrealised exchange losses 204 176 Other temporary differences 1,046 931 Total 6,465 5,967 Deferred tax liabilities arising from: Capital allowances (4,966) (4,742) Unremitted earnings (e) (402) (411) Capitalised interest (351) (387) Post-retirement benefits (224) (253) Unrealised exchange gains (7) (3) Other temporary differences (369) (289) Total (6,319) (6,085) Credited /(charged) to the income statement Unrealised exchange losses 25 (21) Tax losses 12 (164) Provisions 188 175 Capital allowances (82) 181 Tax on unremitted earnings 1 (5) Post-retirement benefits 9 (18) Other temporary differences 25 141 Total 178 289 (a) The amounts credited directly to the statement of comprehensive income include provisions for tax on exchange differences on intragroup loans qualifying for reporting as part of the net investment in subsidiaries, on cash flow hedges and on actuarial gains and losses on pension schemes and on post-retirement healthcare plans. (b) “Other movements” include deferred tax relating to tax payable recognised by subsidiary holding companies on the profits of the equity accounted units to which it relates. (c) There is a limited time period, the shortest of which is one year , for the recovery of US$1,617 million ( 2019 : US$1,186 million; six years ) of tax losses and other tax assets which have been recognised as deferred tax assets in the financial statements. (d) Recognised and unrecognised deferred tax assets are shown in the table below and totalled US$7,226 million at 31 December 2020 ( 2019 : US$6,264 million ). Of this total, US$3,385 million has been recognised as deferred tax assets ( 2019 : US$3,102 million ), leaving US$3,841 million ( 2019 : US$3,162 million ) unrecognised, as recovery is not considered probable. (e) Deferred tax liabilities are not recognised on the unremitted earnings of subsidiaries and joi nt ventures totalling US$2,895 million ( 2019 : US$3,861 million ) where the Group is able to control the timing of the remittance and it is probable that there will be no remittance in the foreseeable future. If these earnings were remitted, tax of US$112 million ( 2019 : US$164 million ) would be payable. The recognised amounts in the table below do not include deferred tax assets that have been netted off against deferred tax liabilities. Analysis of deferred tax assets Recognised Unrecognised 2020 US$m 2019 US$m 2020 US$m 2019 US$m France — — 1,284 1,111 Canada 617 492 574 566 US 938 920 84 51 Australia 649 698 528 316 Mongolia (a) 974 704 540 721 Other 207 288 831 397 Total (b) 3,385 3,102 3,841 3,162 (a) Deferred tax assets in Mongolia include US$292 million (2019: US$130 million) from tax losses that expire if not recovered against taxable profits within eight years. Tax losses have been calculated in accordance with the tax stability provisions of the Oyu Tolgoi Investment Agreement and Mongolian laws. Recovery of the recognised deferred tax assets is expected to commence from 2021 based on projected cash flows, consistent with the latest life of mine plan described in note 6. The interpretation of the stabilised tax laws by the Mongolian Tax Authority has been, and is expected to continue to be, subject to dispute. Changes to agreements or their interpretation could have a material impact on the amount and period of recovery of deferred tax assets. (b) US$720 million (2019: US$695 million) of the unrecognised assets relate to realised or unrealised capital losses, the recovery of which depends on the existence of capital gains in future years. There are time limits, the shortest of which is one year, for the recovery of US$551 million of the unrecognised assets (2019: US$491 million).

Receivables and other assets

Receivables and other assets	12 Months Ended
	Dec. 31, 2020
Trade and other receivables [abstract]
Receivables and other assets	18 Receivables and other assets Non-current 2020 US$m Current 2020 US$m Total 2020 US$m Non-current 2019 US$m Current 2019 US$m Total 2019 US$m Trade receivables (a) 1 2,543 2,544 1 2,097 2,098 Other financial receivables (a) 339 332 671 286 453 739 Receivables relating to net investment in finance leases (a) 29 9 38 52 11 63 Amounts due from equity accounted units (a) — 33 33 — 38 38 Other receivables (b) 369 422 791 123 209 332 Prepayment of tolling charges to jointly controlled entities (c) 218 — 218 221 — 221 Pension surpluses (note 42) 782 — 782 984 — 984 Other prepayments 58 305 363 49 219 268 Total 1,796 3,644 5,440 1,716 3,027 4,743 (a) At 31 December 2020, trade and other financial receivables, receivables relating to net investment in finance leases and amounts due from equity accounted units are stated net of allowances for expected credit losses of US$59 million (20 19: US$54 million). (b) At 31 December 2020, other non-current receivables included US$315 million (2019: US$53 million) and other current receivables US$95 million (2019: US$nil) related to Energy Resources of Australia Ltd (ERA's) deposit held in a trust fund which is controlled by the Government of Australia. During 2020, ERA deposited US$299 million into the trust fund which is recorded in "Other investing cash flows" in the Group cash flow statement. ERA are entitled to reimbursement from the fund once specific phases of rehabilitation relating to the Ranger Project are completed. The fund is outside of the scope of IFRS 9 - "Financial Instruments" and therefore classified as an "other receivable" within "Receivables and other assets". (c) These prepayments will be charged to Group operating costs as tolling services are rendered and product processing occurs. There is no material element of receivables and other assets that is interest-bearing or financing in nature.

Other financial assets

Other financial assets	12 Months Ended
	Dec. 31, 2020
Disclosure Of Other Financial Assets [Abstract]
Other financial assets	19 Other financial assets Non-current 2020 US$m Current 2020 US$m Total 2020 US$m Non-current 2019 US$m Current 2019 US$m Total 2019 US$m Derivative financial instruments 531 134 665 308 58 366 Equity shares and quoted funds 66 9 75 52 9 61 Other investments, including loans (a) 231 2,668 2,899 236 2,603 2,839 Loans to equity accounted units 1 40 41 39 — 39 Total 829 2,851 3,680 635 2,670 3,305 (a) Current “Other investments, including loans” includes US$2,538 million (2019: US$2,584 million) of highly liquid financial assets held in managed investment funds classified as held for trading. Detailed information relating to other financial assets is given in note 29.

Cash and cash equivalents

Cash and cash equivalents	12 Months Ended
	Dec. 31, 2020
Cash and cash equivalents [abstract]
Cash and cash equivalents	20 Cash and cash equivalents 2020 US$m 2019 US$m Cash at bank and in hand 1,150 978 Money market funds, reverse repurchase agreements and other cash equivalents (a) 9,231 7,049 Balance per Group balance sheet and Group cash flow statement 10,381 8,027 (a) We continue to diversify the financial products we invest our surplus cash in. During the year, we purchased securities under resale agreements ("reverse repurchase agreements”). At 31 December 2020 we held US$1,200 million of reverse repurchase agreements, measured at amortised cost and reported within cash and cash equivalents as they are highly liquid products maturing within three months. We accepted collateral of investment grade quality in respect of these reverse repurchase agreements, with a fair value of US$1,260 million as at 31 December 2020. Collateral is not recognised on our balance sheet and in the event of counterparty's default we would be able to sell it. Restricted cash and cash equivalent analysis Cash and cash equivalents of US$295 million (2019: US$315 million) are held in countries where there are restrictions on remittances. Of this balance, US$238 million (2019: US$245 million) could be used to repay subsidiaries’ third-party borrowings. There are also restrictions on a further US$1,422 million (2019: US$1,644 million) of cash and cash equivalents, the majority of which is held by partially owned subsidiaries and is not available for use in the wider Group due to legal and contractual restrictions currently in place. Of this balance US$1,215 million ( 2019 : US$1,442 million ) could be used to repay subsidiaries’ third-party borrowings.

Borrowings and other financial

Borrowings and other financial liabilities	12 Months Ended
	Dec. 31, 2020
Borrowings And Other Financial Liabilities [Abstract]
Borrowings and other financial liabilities	21 Borrowings and other financial liabilities Borrowings at 31 December Note Non-current 2020 US$m Current 2020 US$m Total 2020 US$m Non-current 2019 US$m Current 2019 US$m Total 2019 US$m Rio Tinto Finance plc Euro Bonds 2.0% due 2020 (a)(b)(c) — — — — 455 455 Rio Tinto Finance plc Euro Bonds 2.875% due 2024 (a)(b) 555 — 555 508 — 508 Rio Tinto Finance (USA) Limited Bonds 3.75% 2025 (a) 1,299 — 1,299 1,229 — 1,229 Rio Tinto Finance (USA) Limited Bonds 7.125% 2028 (a) 1,005 — 1,005 958 — 958 Alcan Inc. Debentures 7.25% due 2028 (a) 109 — 109 104 — 104 Rio Tinto Finance plc Sterling Bonds 4.0% due 2029 (a)(b) 717 — 717 647 — 647 Alcan Inc. Debentures 7.25% due 2031 (d) 438 — 438 419 — 419 Alcan Inc. Global Notes 6.125% due 2033 (d) 744 — 744 742 — 742 Alcan Inc. Global Notes 5.75% due 2035 (d) 292 — 292 289 — 289 Rio Tinto Finance (USA) Limited Bonds 5.2% 2040 (a) 1,173 — 1,173 1,137 — 1,137 Rio Tinto Finance (USA) plc Bonds 4.75% 2042 (a) 501 — 501 483 — 483 Rio Tinto Finance (USA) plc Bonds 4.125% 2042 (a) 743 — 743 716 — 716 Oyu Tolgoi LLC MIGA Insured Loan LIBOR plus 2.65% due 2027 (e) 674 4 678 676 3 679 Oyu Tolgoi LLC Commercial Banks "B Loan" LIBOR plus 3.4% due 2027 (e) 1,571 10 1,581 1,581 8 1,589 Oyu Tolgoi LLC Export Credit Agencies Loan 2.3% due 2028 (e) 275 2 277 273 3 276 Oyu Tolgoi LLC Export Credit Agencies Loan LIBOR plus 3.65% due 2029 (e) 867 5 872 869 5 874 Oyu Tolgoi LLC International Financial Institutions "A Loan" LIBOR plus 3.78% due 2030 (e) 771 6 777 771 4 775 Other secured loans 246 68 314 302 45 347 Other unsecured loans 322 256 578 382 197 579 Lease liabilities 22 945 233 1,178 1,007 302 1,309 Total borrowings including overdrafts (f) 13,247 584 13,831 13,093 1,022 14,115 (a) These borrowings are subject to hedging arrangements and are summarised in the interest rate risk section of note 29. (b) Rio Tinto has a US$10 billion (2019: US$10 billion) European Debt Issuance Programme against which the cumulative amount utilised was US$1.2 billion equivalent at 31 December 2020 (2019: US$1.6 billion). The carrying value of these bonds after hedge accounting adjustments amounted to US$1.3 billion (2019: US$1.6 billion) in aggregate. (c) On 11 May 2020, we repaid our €402 million (nominal value) Rio Tinto Finance plc Euro Bonds on their maturity. The cash outflow relating to the repayment of the bonds and the realised loss on the derivatives have been recognised within "Repayment of borrowings and associated derivatives" in the Group cash flow statement and totalled US$526 million. (d) In 2020 we entered into new swaps to convert the interest payable in relation to these bonds from fixed to floating rates. Refer to Note 29 for more details. (e) These borrowings relate to the Oyu Tolgoi LLC project finance facility. The project finance facility provides for interest-only payments for the first five years from 2016 followed by minimum repayments according to a stepped amortisation schedule for the remaining life of the facility. The due dates stated represent the final repayment date. The interest rates stated are pre-completion and will increase by 1% post-completion. (f) The Group’s borrowings of US$13.8 billion (2019: US$14.1 billion) include US$4.5 billion (2019: US$4.5 billion) of subsidiary entity borrowings that are subject to various financial and general covenants with which the respective borrowers were in compliance as at 31 December 2020 . Other financial liabilities Non-current 2020 US$m Current 2020 US$m Total 2020 US$m Non-current 2019 US$m Current 2019 US$m Total 2019 US$m Derivative financial instruments 161 23 184 248 103 351 Other financial liabilities (a) — — — — 247 247 Total other financial liabilities 161 23 184 248 350 598 Total borrowings including overdrafts (as above) 13,247 584 13,831 13,093 1,022 14,115 Total borrowings and other financial liabilities 13,408 607 14,015 13,341 1,372 14,713 (a) At 31 December 2019, other financial liabilities included US$207 million in relation to the share buy-back programme, which was completed in February 2020.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Disclosure of leases [Abstract]
Leases	22 Leases Lessee arrangements We have made the following payments associated with leases: Description of payment 2020 2019 Included within Principal lease payments 324 315 Cash flows from financing activities Interest payments on leases 50 53 Cash flows from operating activities Payments for short-term leases 314 327 Net operating costs Payments for variable lease components 30 15 Net operating costs Payments for low value leases (>12 months in duration) 1 1 Net operating costs Total lease payments 719 711 22 Leases continued Lease liabilities The maturity profile of lease liabilities recognised at the balance sheet date is: Note 2020 US$m 2019 US$m Lease liabilities Due within 1 year 271 349 Between 1 and 3 years 386 424 Between 3 and 5 years 185 226 More than 5 years 724 671 Total undiscounted cash payments expected to be made 1,566 1,670 Effect of discounting (388) (361) Present value of minimum lease payments 21 1,178 1,309

Consolidated net cash_(debt)

Consolidated net cash/(debt)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Consolidated Net Debt [Abstract]
Consolidated net cash/(debt)	23 Consolidated net (debt)/cash Financing liabilities Other assets Year ended 31 December 2020 Borrowings excluding overdrafts (a) US$m Lease liabilities (b) US$m Debt-related derivatives (included in Other financial assets/liabilities) (c) US$m Cash and cash equivalents (d) US$m Other investments (e) US$m Net Analysis of changes in consolidated net debt Opening balance (12,806) (1,309) (147) 8,027 2,584 (3,651) Foreign exchange adjustment (83) (47) 39 165 — 74 Cash movements excluding exchange movements 505 324 91 2,189 (58) 3,051 Other non-cash movements (269) (146) 265 — 12 (138) Closing balance (12,653) (1,178) 248 10,381 2,538 (664) Year ended 31 December 2019 Financing liabilities Other assets Borrowings excluding overdrafts (a) US$m Lease liabilities (b) US$m Debt-related derivatives (included in Other financial assets/ liabilities) (c) US$m Cash and cash equivalents (d) US$m Other investments (e) US$m Net Analysis of changes in consolidated net (debt)/cash Opening balance (12,707) (44) (288) 10,772 2,522 255 Adjustment for transition to new accounting standard (f) — (1,248) — — — (1,248) Foreign exchange adjustment (5) (9) 3 (54) — (65) Cash movements excluding exchange movements 123 315 — (2,808) 28 (2,342) Other non-cash movements (217) (323) 138 117 34 (251) Closing balance (12,806) (1,309) (147) 8,027 2,584 (3,651) (a) Borrowings excluding overdrafts and including lease liabilities at 31 December 2020 of US$13,831 million (2019: US$14,115 million) differ from total borrowings and other financial liabilities of US$14,015 million (2019: US$14,713 million) on the balance sheet as they exclude other current financial liabilities of US$23 million (2019: US$350 million) and other non-current financial liabilities of US$161 million (2019: US$248 million). (b) Other movements in lease liabilities include the net impact of additions, modifications and terminations during the year. (c) Included within "Debt-related derivatives" are interest rate and cross currency interest rate swaps that are in hedge relationships with the Group's debt. (d) Other non-cash movements in the year ended 31 December 2019 of US$117 million represents the elimination of cash movements during the year in respect of assets held for sale which are included in the cash flow statement. (e) Other investments comprise US$2,538 million (2019: US$2,584 million) of highly liquid financial assets held in managed investment funds classified as held for trading. (f) The impact of the transition to new accounting pronouncement IFRS 16 “Leases” on 1 January 2019. Further information relating to the currency and interest rate exposures arising from net debt and related derivatives is given in note 29.

Trade and other payables

Trade and other payables	12 Months Ended
	Dec. 31, 2020
Trade and other payables [abstract]
Trade and other payables	24 Trade and other payables Non-current 2020 US$m Current 2020 US$m Total 2020 US$m Non-current 2019 US$m Current 2019 US$m Total 2019 US$m Trade payables 1 3,124 3,125 — 2,855 2,855 Other financial payables 298 862 1,160 272 668 940 Other payables 97 115 212 110 97 207 Deferred income (a) 133 344 477 143 200 343 Accruals 27 1,294 1,321 27 1,305 1,332 Employee entitlements — 762 762 — 650 650 Royalties and mining taxes 3 863 866 4 596 600 Amounts owed to equity accounted units 190 51 241 167 104 271 Government grants deferred 71 6 77 71 5 76 Total 820 7,421 8,241 794 6,480 7,274 (a) Deferred income includes contract liabilities of US$338 million ( 2019 : US$158 million ).

Provisions (including post-reti

Provisions (including post-retirement benefits)	12 Months Ended
	Dec. 31, 2020
Disclosure of other provisions [abstract]
Provisions (including post-retirement benefits)	25 Provisions (including post-retirement benefits) Note Pensions and post-retirement healthcare (a) US$m Other employee entitlements (b) US$m Close-down and restoration/ environmental (c) US$m Other Total 2020 US$m Total 2019 US$m At 1 January 2,714 354 11,090 945 15,103 13,608 Adjustment to opening balance on transition to new accounting standard (d) — — — — — (66) Restated opening balance 2,714 354 11,090 945 15,103 13,542 Adjustment on currency translation 83 34 736 37 890 65 Adjustments to mining properties/right of use assets: 14 – increases to existing and new provisions — — 130 11 141 840 – change in discount rate — — 816 — 816 — Charged/(credited) to profit: – increases to existing and new provisions 200 127 562 185 1,074 850 – change in discount rate — — 138 2 140 — – unused amounts reversed — (19) (123) (157) (299) (100) – exchange losses on provisions — — (21) (1) (22) 3 – amortisation of discount — — 373 4 377 387 Utilised in year (192) (77) (366) (139) (774) (744) Actuarial losses recognised in equity 250 — — — 250 235 Transfers and other movements — — — (31) (31) 25 At 31 December 3,055 419 13,335 856 17,665 15,103 Balance sheet analysis: Current 70 327 777 555 1,729 1,399 Non-current 2,985 92 12,558 301 15,936 13,704 Total 3,055 419 13,335 856 17,665 15,103 Projected cash spend for the undiscounted close-down and restoration/environmental clean up provision Undiscounted close-down and environmental restoration cash flows <1yr 1-3 yrs 3-5 yrs > 5 yrs Total US$m At 31 December 2020 776 1,203 1,433 13,988 17,400 At 31 December 2019 541 955 1,100 13,470 16,066 (a) The main assumptions used to determine the provision for pensions and post-retirement healthcare, and other information, including the expected level of future funding payments in respect of those arrangements, are given in note 42. (b) The provision for other employee entitlements includes a provision for long service leave of US$283 million ( 2019: US$248 million), based on the relevant entitlements in certain Group operations and includes US$62 million (2019: US$30 million) of provision for redundancy and severance payments. (c) The Group’s policy on close-down and restoration costs is described in note 1(l) and in paragraph (iii) under “Critical accounting policies and estimates” on page 219. Close-down and restoration costs are a normal consequence of mining, and the majority of close-down and restoration expenditure is incurred in the years following closure of the mine, refinery or smelter. Non-current provisions for close-down and restoration/environmental expenditure include amounts relating to environmental clean-up of US$468 million ( 2019: US$382 million) expected to take place between one and five years from the balance sheet date, and US$937 million (2019: US$883 million) expected to take place later than five years after the balance sheet date. Close-down and restoration/environmental liabilities at 31 December 2020 have not been adjusted for closure related receivables amounting to US$574 million (31 December 2019: US$166 million) due from the ERA trust fund, the co-owners of the Diavik Joint Venture and other financial assets held for the purposes of meeting closure obligations. (d) Impact of the transition to new accounting pronouncement IFRS 16 “Leases” on 1 January 2019. 25 Provisions (including post-retirement benefits) continued Analysis of close-down and restoration/environmental clean up provisions As at 31 December Undiscounted close-down and environmental restoration obligations 17,400 16,066 Impact of discounting (4,065) (4,976) Present closure obligation 13,335 11,090 Attributable to: Operating sites 10,736 9,255 Non-operating sites 2,599 1,835 Total 13,335 11,090 Remaining lives of operations and infrastructure range from one to over 50 years with an average for all sites, weighted by present closure obligation, of around 17 years (2019: 18 years). Although the ultimate cost to be incurred is uncertain, the Group’s businesses estimate their respective costs based on current restoration standards, techniques and expected climate conditions. Provisions of US$13,335 million (2019: US$11,090 million) for close-down and restoration costs and environmental clean-up obligations are based on risk-adjusted cash flows. The Group completed a review of the discount rate used to present value the obligations on 30 September 2020 and updated it to a real-rate of 1.5%, applied prospectively from that date. Prior to 30 September 2020 and in recent years, the close-down and restoration costs and environmental clean-up obligations were discounted at a real-rate of 2.0%. To illustrate the sensitivity of the provision to discounting, if the discount rate at 31 December 2020 was decreased to 1.0% then the provision would be US$1.3 billion higher, of which approximately US$1.2 billion would be capitalised within "Property, plant and equipment" at operating sites and US$0.1 billion would be charged to the income statement for non-operating and fully impaired sites. If the discount rate was increased to 3.0% then the provision would be US$2.6 billion lower, of which approximately US$2.4 billion would result in a decrease within "Property, plant and equipment" at operating sites and US$0.2 billion would be credited to the income statement for non-operating and fully impaired sites. Closure cost composition as at 31 December Decommissioning, decontamination and demolition 3,131 2,066 Closure and rehabilitation earthworks (a) 4,223 3,889 Long-term water management costs (b) 966 920 Post closure monitoring and maintenance 1,318 855 Indirect costs, owners' costs and contingency (c) 3,697 3,360 Total 13,335 11,090 The underlying costs for closure have been estimated with varying degrees of accuracy based on a function of the age of the underlying asset and proximity to closure. For assets within ten years of closure, closure plans and cost estimates are supported by detailed studies which are refined as the closure date approaches. These closure studies consider climate change and plan for resilience to expected climate conditions with a particular focus on precipitation rates. For new developments, consideration of climate change and ultimate closure conditions are an important part of the approval process. For longer-lived assets, closure provisions are typically based on conceptual level studies that are refreshed at least every five years; these are evolving to incorporate greater consideration of forecast climate conditions at closure. (a) A key component of earthworks rehabilitation involves re-landscaping the area disturbed by mining activities utilising the largely diesel powered heavy mobile equipment. In developing low-carbon solutions for our mobile fleet, this may include electrification of the vehicles during the mine life. The forecast cash flows for the heavy mobile equipment in the closure cost estimate are based on existing fuel sources; these could reduce if this power is sourced from renewable energy. (b) Long-term water management relates to the post-closure treatment of water due to acid rock drainage and other environmental commitments and is an area of research and development focus for our Closure team. The cost of this water processing can continue for many years after the bulk earthworks and demolition activities have completed and are therefore exposed to long-term climate change. This could materially affect rates of precipitation and therefore change the volume of water requiring processing. It is not currently possible to forecast accurately the impact this could have on the closure provision as some of our locations could experience drier conditions whereas others could experience greater rainfall. A further consideration relates to the alternative commercial use for the processed water which could support ultimate transfer of these costs to a third party. (c) Indirect costs, owners' costs and contingency include adjustments to the underlying cash flows to align the closure provision with a central-case estimate. This excludes allowances for quantitative estimation uncertainties which are allocated to the underlying cost driver and presented within the respective cost categories above. Geographic composition as at 31 December Australia 7,076 5,610 USA 3,819 3,377 Canada 1,482 1,267 Rest of World 958 836 Total 13,335 11,090 The geographic composition of the closure provision shows that our closure obligations are largely in countries with established levels of regulation in respect of mine and site closure.

Share capital - Rio Tinto plc

Share capital - Rio Tinto plc	12 Months Ended
	Dec. 31, 2020
Disclosure of classes of share capital [abstract]
Share capital - Rio Tinto plc	26 Share capital – Rio Tinto plc 2020 Number (million) 2019 Number (million) 2018 Number (million) 2020 US$m 2019 US$m 2018 US$m Issued and fully paid up share capital of 10p each At 1 January 1,259.345 1,287.660 1,351.609 207 211 220 Ordinary shares issued (a)(c) 0.039 0.041 0.035 — — — Shares purchased and cancelled (b) (3.628) (28.356) (63.984) — (4) (9) At 31 December 1,255.756 1,259.345 1,287.660 207 207 211 Shares held by public At 1 January 1,249.924 1,278.215 1,342.058 Shares reissued from treasury (a) 0.569 0.024 0.106 Ordinary shares issued (a)(c) 0.039 0.041 0.035 Shares purchased and cancelled (b) (3.628) (28.356) (63.984) At 31 December 1,246.904 1,249.924 1,278.215 Shares held in treasury 8.852 9.421 9.445 Shares held by public 1,246.904 1,249.924 1,278.215 Total share capital 1,255.756 1,259.345 1,287.660 Other share classes Special Voting Share of 10p each (d) 1 only 1 only 1 only DLC Dividend Share of 10p each (d) 1 only 1 only 1 only Equalisation Share of 10p each (d) 1 only 1 only 1 only (a) 39,273 ordinary shares were issued in 2020 under the Global Employee Share Plan (GESP). 568,863 ordinary shares were reissued from treasury during the year resulting from the vesting of awards under Rio Tinto plc employee share-based payment plans, with market values between £32.74 and £56.32 per share (2019: 40,974 ordinary shares were issued under the GESP and 23,659 ordinary shares were reissued from treasury with exercise prices and market values between £36.33 and £49.74 per share; 2018: 35,380 ordinary shares were issued under the GESP and 106,045 ordinary shares reissued from treasury with exercise prices and market values between £16.53 and £43.79 per share). (b) The authority for the company to buy back its ordinary shares was renewed at the 2020 annual general meeting. 3,627,568 shares were bought back and cancelled in 2020 under the on-market buy-back programme. 28,356,034 shares were bought back and cancelled in 2019 under the on-market buy-back programme. 63,984,287 shares were bought back in 2018 under the on-market buy-back programme. (c) The aggregate consideration for new shares issued under the GESP was US$1.3 million (2019: US$1.1 million; 2018: US$1.0 million). The difference between the nominal value and the issue price of the shares issued was credited to the share premium account. The aggregate consideration received for treasury shares reissued was US$1 million (2019: US$1 million; 2018: US$6 million). No new shares were issued as a result of the exercise of options under Rio Tinto plc employee share-based payment plans in 2020, 2019 and 2018. (d) The “Special Voting Share” was issued to facilitate the joint voting by shareholders of Rio Tinto plc and Rio Tinto Limited on Joint Decisions, following the DLC Merger. The “DLC Dividend Share” was issued to facilitate the efficient management of funds within the DLC structure. Directors have the ability to issue an Equalisation Share if that is required under the terms of the DLC Merger Sharing Agreement. During 2020, US$31 million of shares and ADRs (2019: US$43 million; 2018: US$140 million) were purchased by employee share ownership trusts on behalf of Rio Tinto plc to satisfy employee share awards on vesting. At 31 December 2020, 273,902 shares and 41,240 ADRs were held in the employee share ownership trusts on behalf of Rio Tinto plc.

Share Capital - Rio Tinto Limit

Share Capital - Rio Tinto Limited	12 Months Ended
	Dec. 31, 2020
Disclosure of classes of share capital [abstract]
Share capital - Rio Tinto Limited	27 Share capital – Rio Tinto Limited 2020 Number (million) 2019 Number (million) 2018 Number (million) 2020 US$m 2019 US$m 2018 US$m Issued and fully paid up share capital At 1 January 371.21 371.21 412.41 3,448 3,477 4,140 Adjustment on currency translation 333 (29) (382) Ordinary shares purchased and cancelled (a) — — (41.20) — — (281) At 31 December 371.21 371.21 371.21 3,781 3,448 3,477 – Special Voting Share (b) 1 only 1 only 1 only – DLC Dividend Share (c) 1 only 1 only 1 only Total share capital 371.21 371.21 371.21 (a) In November 2018, 41,198,134 Rio Tinto Limited ordinary shares were purchased at A$69.69 per share and cancelled under an off-market share buy-back programme carried out pursuant to the shareholder approval granted at Rio Tinto Limited’s 2018 annual general meeting for off-market and on-market buy-backs of up to 41.2 million Rio Tinto Limited ordinary shares. (b) The “Special Voting Share” was issued to facilitate the joint voting by shareholders of Rio Tinto Limited and Rio Tinto plc on Joint Decisions following the DLC Merger. The “DLC Dividend Share” was issued to facilitate the efficient management of funds within the DLC structure. Directors have the ability to issue an Equalisation Share if that is required under the terms of the DLC Merger Sharing Agreement. During 2020, US$76 million of shares (2019: US$63 million; 2018: US$114 million) were purchased by employee share ownership trusts on behalf of Rio Tinto Limited to satisfy employee share awards on vesting. At 31 December 2020, 828,338 shares were held in the employee share ownership trusts on behalf of Rio Tinto Limited. Information relating to share-based incentive schemes is given in note 41.

Other reserves and retained ear

Other reserves and retained earnings	12 Months Ended
	Dec. 31, 2020
Disclosure Of Other Reserves And Retained Earnings [Abstract]
Other reserves and retained earnings	28 Other reserves and retained earnings 2020 US$m 2019 US$m 2018 US$m Capital redemption reserve (a) At 1 January 51 47 38 Own shares purchased and cancelled — 4 9 At 31 December 51 51 47 Cash flow hedge reserve At 1 January 160 195 32 Adjustment for transition to new accounting pronouncements (b) — — (4) Cash flow hedge gains 24 12 156 Cash flow hedge (gains)/losses transferred to the income statement (63) (41) 40 Tax on the above 3 (6) (54) Transfers and other movements — — 25 At 31 December 124 160 195 Available for sale revaluation reserves At 1 January — — 20 Adjustment for transition to new accounting pronouncements (b) — — (20) Gains on available for sale securities — — — Losses on available for sale securities transferred to the income statement — — — Tax on the above — — — Transfers and other movements — — — At 31 December — — — Fair value through other comprehensive income reserve At 1 January (11) (6) — Adjustment for transition to new accounting pronouncements (b) — — 8 Losses on equity investments 9 (5) (11) Transfers to retained earnings — — (3) At 31 December (2) (11) (6) Cost of hedging reserve At 1 January (10) (13) — Adjustment for transition to new accounting pronouncements (b) — — 26 Cost of hedging deferred to reserves during the year 7 3 (36) Transfer of cost of hedging to the income statement — — (3) At 31 December (3) (10) (13) Other reserves (c) At 1 January 11,643 11,650 11,714 Own shares purchased from Rio Tinto Limited shareholders to satisfy share options (76) (63) (114) Employee share options: value of services 60 52 52 Deferred tax on share options 1 4 (2) At 31 December 11,628 11,643 11,650 Foreign currency translation reserve (d) At 1 January (2,656) (3,212) 480 Parent and subsidiaries' currency translation and exchange adjustments 2,814 331 (3,658) Equity accounted units currency translation adjustments 4 10 (48) Currency translation reclassified on disposal — 215 14 At 31 December 162 (2,656) (3,212) Total other reserves per balance sheet 11,960 9,177 8,661 28 Other reserves and retained earnings continued 2020 US$m 2019 US$m 2018 US$m Retained earnings (e) At 1 January 23,387 27,025 23,761 Adjustment for transition to new accounting pronouncements (b) — (113) (179) Parent and subsidiaries' profit for the year 9,456 7,709 13,125 Equity accounted units' profit after tax for the year 313 301 513 Actuarial (losses)/gains (f) (482) (259) 894 Tax relating to components of other comprehensive income 116 81 (269) Total comprehensive income for the year 9,403 7,832 14,263 Share buy-back programme (1) (1,135) (5,423) Dividends paid (6,132) (10,334) (5,356) Change in equity interest held by Rio Tinto 84 85 60 Own shares purchased/treasury shares reissued for share options and other movements (31) (43) (140) Employee share options and other IFRS 2 charges taken to the income statement 82 70 61 Transfer from FVOCI reserve — — 3 Transfers and other movements — — (25) At 31 December 26,792 23,387 27,025 (a) The capital redemption reserve was set up to comply with section 733 of the UK Companies Act 2006 (previously section 170 of the UK Companies Act 1985) when shares of a company are redeemed or purchased wholly out of the company’s profits. Balances reflect the amount by which the company’s issued share capital is diminished in accordance with this section. (b) The impact of the transition to new accounting pronouncements; IFRS 16 “Leases” and IFRIC 23 "Uncertainty over income tax treatments" on 1 January 2019 and IFRS 9 “Financial Instruments” and IFRS 15 "Revenue from Contracts with Customers" on 1 January 2018. (c) Other reserves includes US$11,936 million which represents the difference between the nominal value and issue price of the shares issued arising from Rio Tinto plc’s rights issue completed in July 2009. No share premium was recorded in the Rio Tinto plc financial statements through the operation of the merger relief provisions of the UK Companies Act 1985. Other reserves also include the cumulative amount recognised under IFRS 2 in respect of options granted but not exercised to acquire shares in Rio Tinto Limited, less, where applicable, the cost of shares purchased to satisfy share options exercised. The cumulative amount recognised under IFRS 2 in respect of options granted but not exercised to acquire shares in Rio Tinto plc is recorded in retained earnings. (d) Exchange differences arising on the translation of the Group’s net investment in foreign controlled companies are taken to the foreign currency translation reserve, as described in note 1(d). The cumulative differences relating to an investment are transferred to the income statement when the investment is disposed of. (e) Retained earnings and movements in reserves of subsidiaries include those arising from the Group’s share of joint operations.

Financial instruments and risk

Financial instruments and risk management	12 Months Ended
	Dec. 31, 2020
Disclosure of detailed information about financial instruments [abstract]
Financial instruments and risk management	29 Financial instruments and risk management In this note, except where stated, the information relates to the financial instruments of the parent companies and their subsidiaries and joint operations, and excludes those of equity accounted units. We have grouped the information in the following sections: A – Financial assets and liabilities by categories B – Derivative financial instruments C – Fair values A (a) Financial assets and liabilities by categories At 31 December 2020 Note Total Amortised Fair value through other Fair value Financial assets Cash and cash equivalents 20 10,381 3,970 — 6,411 Trade and other financial receivables (a)(b) 18 3,286 1,479 — 1,807 Equity shares and quoted funds 19 75 — 64 11 Other investments, including loans (c) 19 2,899 138 — 2,761 Derivatives related to net debt: designated as hedges (d) 19, 23 388 — — 388 Derivatives and embedded derivatives not related to net debt: not designated as hedges (d) 19 204 — — 204 Embedded derivatives not related to net debt: designated as hedges (d) 19 73 — — 73 Loans to equity accounted units including quasi equity loans 153 153 — — Total financial assets 17,459 5,740 64 11,655 Financial liabilities Trade and other financial payables (e) 24 (5,847) (5,817) (30) Short-term borrowings and bank overdrafts 21 (584) (584) — Medium-term and long-term borrowings 21 (13,247) (13,247) — Derivatives related to net debt: designated as hedges (d) 21, 23 (140) — (140) Derivatives and embedded derivatives not related to net debt: not designated as hedges (d) 21 (24) — (24) Embedded derivatives not related to net debt: designated as hedges (d) 21 (20) — (20) Other financial liabilities 21 — — — Total financial liabilities (19,862) (19,648) (214) At 31 December 2019 Note Total Amortised Fair value Fair value Financial assets Cash and cash equivalents 20 8,027 2,707 — 5,320 Trade and other financial receivables (a)(b) 18 2,938 1,801 — 1,137 Equity shares and quoted funds 19 61 — 50 11 Other investments, including loans (c) 19 2,839 21 — 2,818 Derivatives related to net debt: designated as hedges (d) 19, 23 151 — — 151 Derivatives and embedded derivatives not related to net debt: not designated as hedges (d) 19 149 — — 149 Embedded derivatives not related to net debt: designated as hedges (d) 19 66 — — 66 Loans to equity accounted units including quasi equity loans 152 152 — — Total financial assets 14,383 4,681 50 9,652 Financial liabilities Trade and other financial payables (e) 24 (5,398) (5,341) (57) Short-term borrowings and bank overdrafts 21 (1,022) (1,022) — Medium-term and long-term borrowings 21 (13,093) (13,093) — Derivatives related to net debt: designated as hedges (d) 21, 23 (298) — (298) Derivatives and embedded derivatives not related to net debt: not designated as hedges (d) 21 (29) — (29) Embedded derivatives not related to net debt: designated as hedges (d) 21 (24) — (24) Other financial liabilities 21 (247) (247) — Total financial liabilities (20,111) (19,703) (408) (a) Trade and other financial receivables comprise trade receivables, other financial receivables, receivables relating to net investments in finance leases and amounts due from equity accounted units within note 18. (b) Provisionally priced receivables are fair valued. (c) Other investments, including loans, includ e US$2,538 million ( 2019: US$2,584 million) of highly liquid financial assets in managed investment funds classified as held for trading. (d) These financial assets and liabilities in aggregate agree to the total derivative financial instruments disclosed in notes 19 and 21. (e) Trade and other financial payables comprise trade payables, other financial payables, accruals and amounts due to equity accounted units within note 24 . The trade and other payables held at fair value are valued using Level 2 inputs. 29 Financial instruments and risk management continued A (b) Financial risk management Objectives and policy Our financial risk management objectives are: – to have in place a robust capital structure to manage the organisation through the commodity cycle; and – to allow our financial exposures to float with the market. Any exceptions to these require formal approval by the Board. The Group operates a floating prices and rates policy for the management of our key economic exposure to commodity price, foreign exchange and interest rates risks. We do not seek to hedge this floating exposure and will re-float, where possible, any material price or rates that are fixed. Where this is impossible (or sub-optimal) any non-floating price risks are managed within defined market risk tolerances. Derivatives are used as and when required in order to manage our exposure in accordance with this underlying financial risk management principle. In the paragraphs below, we summarise the risks that we are exposed to, and outline how our Treasury and Commercial teams manage these risks in accordance with agreed policies. These teams operate under a strong control environment, within approved limits. Our Board reviews and approves limits at least annually. (i) Capital and liquidity risk Our overriding objective when managing capital and liquidity is to safeguard the business as a going concern. Capital is allocated in a consistent and disciplined manner, prioritising sustaining capital expenditure, followed by the ordinary dividend and then an iterative allocation between investing in compelling growth opportunities, maintaining balance sheet strength and delivering further returns to shareholders. Our Board and senior management regularly review the capital structure and liquidity of the Group. They take into account our strategic priorities, the economic and business conditions, and any identified investment opportunities, along with the expected returns to shareholders. We expect total cash returns to shareholders over the longer term to be in a range of 40–60% of underlying earnings in aggregate through the commodity cycle. We consider various financial metrics when managing our risk, including net debt, gearing, the overall level of borrowings and their maturity profile, liquidity levels, total capital, future cash flows, underlying EBITDA and interest cover ratios. Our total capital as at 31 December was: Total capital Note 2020 US$m 2019 US$m Equity attributable to owners of Rio Tinto (see Group balance sheet) 47,054 40,532 Equity attributable to non-controlling interests (see Group balance sheet) 4,849 4,710 Net debt 23 664 3,651 Total capital 52,567 48,893 Our net debt decreased to US$0.7 billion at 31 December 2020 from US$3.7 billion at 31 December 2019. This was driven by operating cash inflows, partially offset by capital expenditure and cash returns to shareholders during the year. At 31 December 2020 net gearing was 1% (2019: 7%) and interest cover was 39 times (2019: 28 times). We have access to various forms of financing including our US Shelf Programme, European Debt Issuance Programme, Commercial Paper and credit facilities. We did not issue any debt in 2020 or 2019 under these programmes. We have US$7.5 billion fully committed Revolving Credit Facilities, which were extended in 2020 to November 2023 and remained undrawn throughout the year. The funds available can be used for general corporate purposes. Advances under these revolving facilities bear an interest rate per annum based on LIBOR (or EURIBOR, CDOR or BBSW in relation to any euro, Canadian dollar or Australian dollar loans respectively) plus a margin (which is dependent on our long-term credit rating as determined by Moody’s and Standard & Poor’s and the level of drawdown). The facility agreements contain no financial covenants. Our credit ratings, as provided by Standard & Poor’s and Moody’s investor services, as at 31 December were: 2020 2019 Long-term rating A/A2 A/A2 Short-term rating A-1/P-1 A-1/P-1 Outlook Stable/Stable Stable/Stable Our unified credit status is maintained through cross guarantees, which mean the contractual obligations of Rio Tinto plc and Rio Tinto Limited are automatically guaranteed by the other. In the table below, we summarise the maturity profile of our financial liabilities based on contractual undiscounted payments, which will therefore not necessarily agree with the amounts disclosed in the balance sheet. Financial liability analysis At 31 December 2020 (Outflows)/Inflows Within 1 Between Between Between Between After Total Non-derivative financial liabilities Trade and other financial payables (a) (5,251) (53) (15) (34) (19) (394) (5,766) Expected lease liability payments (271) (231) (155) (101) (84) (724) (1,566) Borrowings before swaps (351) (667) (743) (1,256) (1,892) (7,477) (12,386) Expected future interest payments (a) (525) (522) (495) (469) (427) (2,999) (5,437) Derivative financial liabilities (b) Derivatives related to net debt – net settled — — — — — — — Derivatives related to net debt – gross settled (a) : – gross inflows 27 27 27 27 27 790 925 – gross outflows (34) (34) (34) (34) (34) (943) (1,113) Derivatives not related to net debt – net settled (20) (7) (2) (2) (2) (9) (42) Derivatives not related to net debt – gross settled: – gross inflows 290 — — — — — 290 – gross outflows (291) — — — — — (291) Total (6,426) (1,487) (1,417) (1,869) (2,431) (11,756) (25,386) At 31 December 2019 Within 1 Between Between Between Between After Total Non-derivative financial liabilities Trade and other financial payables (a) (4,841) (45) (12) (14) (15) (380) (5,307) Expected lease liability payments (349) (267) (157) (133) (93) (671) (1,670) Borrowings before swaps (723) (171) (665) (741) (1,209) (9,320) (12,829) Expected future interest payments (a) (607) (594) (590) (551) (514) (3,518) (6,374) Other financial liabilities (247) — — — — — (247) Derivative financial liabilities (b) Derivatives related to net debt – net settled (16) (16) (16) 9 (3) 3 (39) Derivatives related to net debt – gross settled (a) : – gross inflows 495 40 40 40 507 788 1,910 – gross outflows (588) (53) (53) (53) (599) (977) (2,323) Derivatives not related to net debt – net settled (31) — — (2) (4) (23) (60) Derivatives not related to net debt – gross settled: – gross inflows 699 — — — — — 699 – gross outflows (703) — — — — — (703) Total (6,911) (1,106) (1,453) (1,445) (1,930) (14,098) (26,943) (a) The interest payable at year end was removed from trade and other financial payables and is shown within expected future interest payments. Interest payments have been projected using interest rates applicable at the end of the applicable financial year. Where debt is subject to variable interest rates, future interest payments are subject to change in line with market rates. (b) The maturity grouping is based on the earliest payment date. Offsetting and enforceable master netting agreements When we have a legally enforceable right to offset our financial assets and liabilities and an intention to settle on a net basis, or realise the asset and settle the liability simultaneously, we report the net amount in the consolidated balance sheet. Agreements with derivative counterparties are based on the International Swaps and Derivatives Association master netting agreements that do not meet the criteria for offsetting, but allow for the related amounts to be set-off in certain circumstances. During the year, there were no material amounts offset in the balance sheet. (ii) Commodity price risk Our broad commodity base means our exposure to commodity prices is diversified. Our normal policy is to sell our products at prevailing market prices. Exceptions to this rule are subject to strict limits laid down by the Board, and to defined market risk tolerances and internal controls. We sell our products to customers under contracts which vary in tenure and pricing mechanisms, including some volumes sold in the spot market. Sales revenue may be subject to adjustment if product specifications do not conform to the terms specified in a sales contract. Pricing for iron ore is on a range of terms, the majority being either monthly or quarterly average pricing mechanisms. We sell a smaller proportion of iron ore volumes on the spot market. 29 Financial instruments and risk management continued (ii) Commodity price risk (continued) We generally sell copper and aluminium under contracts which vary in tenure and pricing mechanisms, with some volumes sold in the spot market. The prices are determined by reference to prevailing market prices on terminal markets, such as the London Metal Exchange (LME) and the Commodities Exchange (COMEX) in New York. Prices fluctuate widely in response to changing levels of supply and demand but, in the long run, prices are related to the marginal cost of supply. Gold is also priced in an active market in which prices respond to daily changes in quantities offered and sought. Newly mined gold is only one source of supply; investment and disinvestment can be important elements of supply and demand. At the date revenue is recognised, certain of our products are provisionally priced, based on the amount we expect to receive in the future. After initial recognition of revenue, we record any change in revenue relating to market prices separately in "Other revenue" (refer to note 3). Substantially all iron ore and aluminium sales are reflected at final prices at each reporting period. Final prices for copper concentrate, however, are normally determined between 30 and 180 days after delivery to our customer. At 31 December 2020, we had 261 million pounds of copper sales, including share of equity accounted unit (31 December 2019: 220 million pounds), that were provisionally priced at US 336 cents per pound (2019: US 271 cents per pound). The final price of these sales will be determined during the first half of 2021. A 10% change in the price of copper realised on the provisionally priced sales, all other factors held constant, would increase or reduce net earnings by US$58 million (2019: US$38 million). For some products, particularly aluminium, we are also exposed to fluctuations in power prices. Hedging strategy We do not generally consider that using derivatives to fix commodity prices would provide a long-term benefit to our shareholders. However, for certain physical commodity transactions for which the price was fixed at the contract date, we enter into derivatives to achieve the prevailing market prices at the point of revenue recognition. To mitigate our exposure to changes in the relationship between aluminium prices and power prices, we have a number of electricity purchase contracts which are directly linked to the daily official LME cash ask price for high grade aluminium (“LME price”) and to the US Midwest Transaction Premium (“Midwest premium”). In accordance with IFRS 9, we apply hedge accounting to two embedded derivatives within our power contracts. The embedded derivatives (notional aluminium forward sales) have been designated as the hedging instrument. The forecasted aluminium sales, priced using the LME price and the Midwest premium, represent the hedged item. The hedging ratio is 1:1, as the quantity of sales designated as being hedged matches the notional amount of the hedging instrument. The hedging instrument’s notional amount, expressed in equivalent metric tonnes of aluminium, is derived from our expected electricity consumption under the power contracts as well as other relevant contract parameters. When we designate such embedded derivatives as the hedging instrument in a cash flow hedge, we recognise the effective portion of the change in the fair value of the hedging instrument in other comprehensive income, and it is accumulated in the cash flow hedge reserve. The amount that is recognised in other comprehensive income is limited to the lesser of the cumulative change in the fair value of the hedging instrument and the cumulative change in the fair value of the hedged item, in absolute terms. We recognise any ineffectiveness relating to the hedging relationship immediately in the income statement. Sources of ineffectiveness include: differences in the timing of the cash flows between the hedged item and the hedging instrument, non-zero initial fair value of the hedging instrument, the existence of a cap on the Midwest premium in the hedging instrument and counterparty credit risk. We held the following notional aluminium forward sales contracts embedded in the power contracts: At 31 December 2020 Total Within 1 year Between 1 and 5 years Between 5 and 10 years After 10 years Notional amount (in tonnes) 640,963 72,548 287,587 280,828 — Notional amount (in US$ millions) 1,522 159 663 701 — Average hedged rate (in US$ per tonne) 2,375 2,189 2,305 2,495 — At 31 December 2019 Total Within 1 year Between 1 Between 5 After 10 years Notional amount (in tonnes) 704,370 65,226 286,617 352,527 — Notional amount (in US$ millions) 1,656 138 647 871 — Average hedged rate (in US$ per tonne) 2,351 2,114 2,257 2,471 — The impact on our financial statements of these hedging instruments and hedging items are: Aluminium embedded derivatives separated from the power contract (Hedging instrument) (a) Highly probable forecast aluminium sales (Hedged item) Nominal Carrying amount Change in fair value in the period Cash flow hedge reserve (b) US$m Change in fair value in Total hedging Hedge ineffective-ness in the period (c) US$m Amount reclassified from reserves to income statement (d) US$m 2020 1,522 46 23 184 (49) 27 (4) 40 2019 1,656 42 29 196 (50) 36 (7) 19 (a) Aluminium embedded derivatives (forward contracts and options) are contained within certain aluminium smelter electricity purchase contracts. US$66 million (2019: US$66 million) of the carrying value is shown within "Other financial assets" and US$20 million (2019: US$24 million) shown within "Other financial liabilities". (b) The difference between this amount and the total cash flow hedge reserve of the Group (shown in n ote 28) relates to our cash flow hedge on the sterling bond (refer to interest rate risk section). (c) Hedge ineffectiveness is included in net operating costs (raw materials, consumables, repairs and maintenance) in the income statement. (d) On realisation of the hedge, realised amounts are reclassified from reserves to consolidated sales revenue in the income statement. There was no cost of hedging recognised in 2020 or 2019 relating to this hedge relationship. We set out details of our commodity derivatives that are not designated as hedges in section B. Sensitivities Our commodity derivatives are impacted by changes in market prices. The table below summarises the impact that changes in aluminium market prices have on aluminium forward and option contracts embedded in power supply agreements outstanding at 31 December 2020. Any change in price will result in an offsetting change in our future earnings. Change in 2020 US$m 2019 US$m Effect on net earnings +10 % (19) (28) (10) % 19 27 Effect on equity +10 % (98) (97) (10) % 100 101 We exclude our “own use contracts” from this sensitivity analysis as they are outside the scope of IFRS 9. Our business units continue to hold these types of contracts to satisfy their expected purchase, sale or usage requirements. (iii) Credit risk We are exposed to credit risk in our operating activities (primarily from customer trade receivables); and from our investing activities (primarily investments in separately managed funds). We are also exposed to credit risk arising from our deposits in treasury and liquidity funds, deposits with banks and financial institutions and from our interest rate and currency derivative contracts. Credit risks related to receivables Our Commercial team manages customer credit risk subject to our established policy, procedures and controls. The team establishes credit limits for all of our customers. Where customers are rated by an independent credit rating agency, these ratings are used as a guide to set credit limits. Where there are no independent credit ratings available, we assess the credit quality of the customer through a credit rating model and assign appropriate credit limit. The Commercial team monitors outstanding customer receivables regularly and highlights any credit concerns to senior management. Receivables to high risk customers are often secured by letters of credit or other forms of credit enhancement. The expected credit loss on our trade receivable portfolio is insignificant (see note 18). Credit risk related to financial instruments and cash deposits Our Treasury team manages credit risk from investments in government securities (primarily US Government), corporate and asset-backed securities, reverse re-purchase agreements, money market funds, and balances with banks and financial institutions in accordance with a Board-approved credit risk framework which sets the risk appetite. Our Board reviews this annually. We make investments of surplus funds only with approved investment grade (BBB- and above) counterparties who have been assigned specific credit limits. The limits are set to minimise the concentration of credit risk and therefore mitigate the potential for financial loss through counterparty failure. 29 Financial instruments and risk management continued The maximum credit risk exposure arising on our financial assets at the balance sheet date is as follows: Note 2020 US$m 2019 US$m Cash and cash equivalents 20 10,381 8,027 Trade and other financial receivables 18 3,286 2,938 Investments 19 2,899 2,839 Derivative assets 19 665 366 Loans to equity accounted units 41 39 Total 17,272 14,209 (iv) Foreign exchange risk The broad geographic spread of our sales and operations means that our earnings, cash flows and shareholders’ equity are influenced by a wide variety of currencies. The majority of our sales are denominated in the US dollar. Our operating costs are influenced by the currencies of those countries where our mines and processing plants are located, and by those currencies in which we buy imported equipment and services. The US dollar, the Australian dollar and the Canadian dollar are the most important currencies influencing our costs. In any particular year, currency fluctuations may have a significant impact on our financial results. A strengthening of the US dollar against the currencies in which our costs are partly denominated has a positive effect on our underlying earnings. However, a strengthening of the US dollar reduces the value of non-US dollar denominated net assets, and therefore total equity. Our external borrowings and cash are mainly denominated in US dollars, either directly or through the use of derivatives, as we consider the US dollar the most appropriate currency for financing our operations. In most cases our debt and other financial assets and liabilities, including intragroup balances, is held in the functional currency of the relevant subsidiary. There are instances where these balances are held in currencies other than the functional currency of the relevant subsidiary. This means we recognise exchange gains and losses in our income statement (except where they can be taken to equity) as these balances are translated into the functional currency of the relevant subsidiary. Our income statement also includes exchange gains and losses arising on US dollar net debt and intragroup balances. On consolidation, these balances are retranslated to our US dollar presentation currency and there is a corresponding and offsetting exchange difference recognised directly in the currency translation reserve. There is no impact on total equity. The table below summarises, by currency, our net debt, after taking into account relevant cross currency interest rate swaps and foreign exchange contracts: Net debt by currency Total Lease liabilities Derivatives Cash and Other Net debt Net debt US dollar (12,102) (342) 248 9,517 2,538 (141) (2,843) Australian dollar (375) (350) — 439 — (286) (561) Euro (4) (25) — 43 — 14 10 South African rand — (1) — 141 — 140 171 Canadian dollar (170) (199) — 36 — (333) (322) Other (2) (261) — 205 — (58) (106) Total (12,653) (1,178) 248 10,381 2,538 (664) (3,651) Hedging strategy Under normal market conditions, we do not consider that active currency hedging of transactions would provide long-term benefits to shareholders. We review our exposure on a regular basis and will undertake hedging if deemed appropriate. We may deem currency protection measures appropriate in specific commercial circumstances. Capital expenditures and other significant financial items such as acquisitions, disposals, tax and dividend cash flows may be economically hedged subject to strict limits laid down by the Board. Details of the cross-currency interest rate swaps and the currency forward contracts used to manage our currency risk exposures at 31 December 2020 are in section B. Sensitivities The table below shows the estimated retranslation effect on financial assets and financial liabilities, including intragroup balances, of a 10% strengthening in the closing exchange rate of the US dollar against significant currencies. We deem 10% to be the annual exchange rate movement that is reasonably probable (on an annual basis over the long run) for any of our significant currencies and therefore an appropriate representation. We calculate sensitivities in relation to the functional currencies of our individual entities. We translate the impact of these on net earnings and underlying earnings into US dollars at the exchange rates on which the sensitivities are based. The impact to net earnings associated with a 10% weakening of a particular currency, shown below, is broadly offset within equity through movements in the currency translation reserve and therefore generally has no impact on our net assets. The impact is expressed in terms of the effect on net earnings, underlying earnings, and equity, assuming that each exchange rate moves in isolation. The sensitivities are based on financial assets and financial liabilities held at 31 December 2020, where balances are not denominated in the functional currency of the subsidiary or joint operation, and exclude financial assets and liabilities held by equity accounted unit s. These balances will not remain constant throughout 2021, and therefore the following information should be used with care. At 31 December 2020 Gains/(losses) associated with 10% strengthening of the US dollar Currency exposure Closing Effect on Of which Impact Australian dollar 77 625 (11) (1,105) Canadian dollar 78 (167) 6 — Euro 123 139 3 — At 31 December 2019 Gains/(losses) associated with 10% strengthening of the US dollar Currency exposure Closing Effect on Of which Impact Australian dollar 70 453 (4) (1,002) Canadian dollar 77 (143) 7 — Euro 112 178 4 — (v) Interest rate risk Our interest rate management policy is generally to borrow and invest at floating interest rates. This approach is based on the historically lower cost of borrowing at floating rates, and the historical correlation between interest rates and commodity prices. It does mean, however, that movements in market interest rates impact our earnings. In certain circumstances, we may elect to maintain a higher proportion of fixed-rate funding. Hedging strategy Because we aim to borrow and invest at floating interest rates, we enter into interest rate swaps and review these positions on a regular basis. During 2020, we entered into US$1.5 billion of interest rate swaps to convert the remaining fixed Alcan debt to floating interest rates. This is in accordance with our floating interest rate policy. We have put these swaps into fair value hedge relationships with the respective tranches of debt. At 31 December 2020 , US$5.9 billion ( 2019 : US$4.5 billion ) US dollar notional fixed-rate US dollar borrowings continue to be swapped to floating US dollar rates and €417 million ( 2019 : €818 million ) euro notional fixed-rate borrowings continue to be fully swapped to floating US dollar interest rates at an effective exchange rate of 1.3105 . Th ese swaps are in fair value hedge relationships. Since 2012, we have also held cross-currency interest rate swaps to convert the principal and annual interest coupons of the Rio Tinto Finance plc £500m Sterling Bond to a US dollar notional with fixed US dollar annual interest coupons. We applied cash flow hedge accounting to this relationship to limit our US dollar cash flow exposure on the principal and interest payments. The hedge was fully effective in the 2020 and 2019 financial years as the notional amount, maturity, payment and reset dates match. 2020 2019 Nominal amount Nominal amount Maturity Effective Gain in fair value of the interest component of the hedged item Loss in fair value of the interest component of the hedging instrument Loss in fair value of the interest component of the hedged item Gain in fair value of the interest component of the hedging instrument £500 million US$807 million November 2029 1.6132 7 (7) (24) 24 In 2019, we swapped the resulting fixed US dollar annual interest coupon payments to floating rates. Fair value hedge accounting has been applied to this relationship in addition to the pre-existing cash flow hedge. 29 Financial instruments and risk management continued The effective interest rates of our borrowings, impacted by swaps, are summarised below. All nominal values are fully hedged unless otherwise stated: Borrowings in a hedge relationship Nominal value Weighted average Swap maturity Carrying value Carrying value Rio Tinto Finance plc Euro Bonds 2.0% due 2020 (a) 526 3 month LIBOR +1.35% 2020 — 455 Rio Tinto Finance plc Euro Bonds 2.875% due 2024 546 3 month LIBOR +1.64% 2024 555 508 Rio Tinto Finance (USA) Limited Bonds 3.75% 2025 1,200 3 month LIBOR +1.39% 2025 1,299 1,229 Rio Tinto Finance (USA) Limited Bonds 7.125% 2028 750 3 month LIBOR +3.27% 2028 1,005 958 Alcan Inc. Debentures 7.25% due 2028 100 3 month LIBOR +5.43% 2024 109 104 Rio Tinto Finance plc Sterling Bonds 4.0% due 2029 807 3 month LIBOR +2.65% 2024 717 647 Alcan Inc. US$400m Debentures 7.25% due 2031 (b) 400 3 month LIBOR +5.72% 2025 438 — Alcan Inc. US$750m Global Notes 6.125% due 2033 (b) 750 3 month LIBOR +5.67% 2025 744 — Alcan Inc. US$300m Global Notes 5.75% due 2035 (b) 300 3 month LIBOR +5.18% 2025 292 — Rio Tinto Finance (USA) Limited Bonds 5.2% 2040 1,150 3 month LIBOR +3.79% 2022 1,173 1,137 Rio Tinto Finance (USA) plc Bonds 4.75% 2042 500 3 month LIBOR +3.42% 2023 501 483 Rio Tinto Finance (USA) plc Bonds 4.125% 2042 750 3 month LIBOR +2.83% 2023 743 716 (a) On 11 May 2020 we repaid, in full, the nominal amount of the Rio Tinto Finance plc Euro Bonds 2% due 2020. (b) In 2020 we entered into new swaps to convert the interest payable in relation to these bonds from fixed to floating rates. The fair value of interest rate and cross currency interest rate swaps at 31 December 2020 was US$388 million ( 2019 : US$151 million ) asset and US$140 million ( 2019 : US$298 million ) liability, respectively. These are included within “Other financial assets” and “Other financial liabilities” in the balance sheet. The main sources of ineffectiveness of the fair value hedges include changes in the timing of the cash flows of the hedging instrument compared to the underlying hedged item, and changes in the credit risk of parties to the hedging relationships. Refer to Note 8 for the changes in fair value of the bonds and the swaps as well as the ineffectiveness recognised in the period. Refer to Note 1 "New standards Issued not yet effective" for the impacts of IBOR reform. Taking into account the interest and currency interest rate swaps, at 31 December 2020, US$11.7 billion ( 2019 : US$10.8 billion ) of our adjusted gross borrowings were at floating rates. This has resulted in a floating to fixed debt ratio of 86% floating to 14% fixed (2019: 76% floating to 24% fixed). Our weighted average debt maturity was approximate ly 9 years ( 2019: 10 years) based on current interest rates and the carrying value of gross borrowings at the year end. Sensitivities Based on our floating rate financial instruments outstanding at 31 December 2020, the effect on our net earnings of a 100 basis point increase in US dollar LIBOR interest rates, with all other variables held constant, would be a n expense of US$7 million ( 2019 : expense of US$20 million), reflecting the lower net debt position in 2020 compared to 2019. We have an exposure to interest rate volatility within shareholders’ equity arising from fair value movements on derivatives in the cash flow hedge reserve. These derivatives have an underlying exposure to sterling and US dollars. With all factors remaining constant, and based on the co

Contingencies and commitments

Contingencies and commitments	12 Months Ended
	Dec. 31, 2020
Disclosure Of Commitments And Contingent Liabilities [Abstract]
Contingencies and commitments	30 Contingencies and commitments 2020 US$m 2019 US$m Capital commitments excluding the Group's share of joint venture capital commitments Within 1 year 3,021 3,069 Between 1 and 3 years 97 851 Between 3 and 5 years — 133 After 5 years 34 — Total 3,152 4,053 Group's share of joint venture capital commitments Within 1 year 9 92 Between 1 and 3 years — 1 Total 9 93 Our capital commitments include open purchase orders for managed operations and expenditure on major projects already authorised by our Investment Committee for non-managed operations. On a legally enforceable basis, capital commitments would be approximately US$1.5 billion (2019: US$0.9 billion) as many of the contracts relating to the Group’s projects have various cancellation clauses. 30 Contingencies and commitments continued Unrecognised commitments to contribute funding or resources to joint ventures We have a commitment to purchase and market a portion (in excess of the Group’s ownership interest) of the output of Sohar Aluminium Company L.L.C., an aluminium smelter in which the Group is a joint venture partner. The Group immediately sells the purchased products to third parties. Along with the other joint venture partners, we have commitments to provide emergency funding (ie funding required to preserve the life or assets of the company or to comply with applicable laws) if required by Sohar Aluminium Company L.L.C., subject to approved thresholds. At 31 December 2020, Minera Escondida Ltda held an undrawn shareholder line of credit for US$225 million (Rio Tinto share) (31 December 2019: US$225 million). The current facility will mature in September 2022. Purchase obligations The aggregate amount of future payment commitments under purchase obligations outstanding at 31 December was: 2020 US$m 2019 US$m Within 1 year 3,100 2,920 Between 1 and 2 years 1,715 1,705 Between 2 and 3 years 1,291 1,431 Between 3 and 4 years 1,242 1,084 Between 4 and 5 years 848 1,082 After 5 years 8,437 8,697 Total 16,633 16,919 Purchase obligations are enforceable and legally binding agreements to buy goods or services. They specify all significant terms, including: fixed or minimum quantities to be purchased or consumed; fixed, minimum or variable price provisions; and the approximate timing of the transactions. Purchase obligations for goods mainly relate to purchases of raw materials and consumables and purchase obligations for services mainly relate to charges for the use of infrastructure, commitments to purchase power and freight contracts. These goods and services are expected to be used in the business. To the extent that this changes, a provision for onerous obligations may be made as described in note 1- critical policy (vii). Purchases from joint arrangements or associates are included if the quantity purchased is in excess of our ownership interest in the entity. However, purchase obligations exclude contracted purchases of bauxite, alumina and aluminium from joint arrangements and associates and contracted purchases of alumina from third parties. This is because these purchases are made for commercial reasons and the Group is, overall, a net seller of these commodities. As described above, we also have a commitment to buy and market a portion (in excess of our ownership interest) of the output of Sohar Aluminium Company L.L.C. Contingent liabilities (subsidiaries and joint operations) 2020 US$m 2019 US$m Indemnities and other performance guarantees (a)(b) 146 204 (a) Indemnities and other performance guarantees represent the potential outflow of funds from the Group for the satisfaction of obligations including those under contractual arrangements (for example undertakings related to supplier agreements) not provided for in the balance sheet, where the likelihood of the guarantees or indemnities being called is assessed as possible rather than probable or remote. (b) There were no material contingent liabilities arising in relation to the Group’s joint ventures and associates. Contingent liabilities In October 2017, Rio Tinto announced that it had been notified by the U.S. Securities and Exchange Commission (SEC) that the SEC had filed a complaint in relation to Rio Tinto’s disclosures and timing of the impairment of Rio Tinto Coal Mozambique (RTCM). The impairment was reflected in Rio Tinto’s 2012 year-end accounts. The SEC alleges that Rio Tinto, a former chief executive, Tom Albanese, and a former chief financial officer, Guy Elliott, committed violations of the antifraud, reporting, books and records and internal control provisions of the federal securities law by not accurately disclosing the value of RTCM and not impairing it when Rio Tinto published its 2011 year-end accounts in February 2012 or its 2012 interim results in August 2012. In June 2019, the trial court dismissed an associated US class action on behalf of securities holders. In August 2020, the appeals court partially overturned the court’s dismissal and the case is with the trial court for further consideration. In March 2018, the Australian Securities and Investments Commission (ASIC) filed civil proceedings in the NSW District Registry of the Federal Court of Australia against Rio Tinto Limited, Albanese, and Elliott. On 1 May 2018, ASIC expanded its proceedings. ASIC alleges that Rio Tinto committed violations of the disclosure, accounting, and misleading or deceptive conduct provisions of the Corporations Act by making misleading or deceptive statements related to RTCM in its 2011 Annual Report and its 2012 interim financial statements, not complying with accounting standards in respect of its 2012 interim financial statements, and not disclosing an impairment of RTCM in its 2012 interim financial statements. ASIC further alleges Albanese and Elliott breached their duties as directors or officers, and failed to take all reasonable steps to comply with relevant accounting requirements. Rio Tinto believes that the SEC case and the ASIC proceedings are unwarranted and will defend the allegations vigorously. Hence, no provisions have been recognised for these cases. Rio Tinto continues to co-operate fully with relevant authorities in connection with their investigations in relation to contractual payments totalling US$10.5 million made to a consultant who had provided advisory services in 2011 on the Simandou project in Guinea. In August 2018, the court dismissed a related US class action commenced on behalf of securities holders. No provision has been recognised for this case. The outcomes of these matters remain uncertain, but they could ultimately expose the Group to material financial cost. The Board is giving these matters its full and proper attention and a dedicated Board committee continues to monitor the progress of these matters, as appropriate. The Group has not established provisions for certain additional legal claims in cases where we have assessed that a payment is either not probable or cannot be reliably estimated. A number of Group companies are, and will likely continue to be, subject to various legal proceedings and investigations that arise from time to time. As a result, the Group may become subject to substantial liabilities that could affect our business, financial position and reputation. Litigation is inherently unpredictable and large judgments may at times occur. The Group may incur, in the future, judgments or enter into settlements of claims that could lead to material cash outflows. We do not believe that any of these proceedings will have a materially adverse effect on our financial position. Guarantees by parent companies Rio Tinto plc and Rio Tinto Limited have, jointly and severally, fully and unconditionally guaranteed the following securities issued by the following 100% owned finance subsidiaries: US$4.4 billion ( 31 December 2019 : US$4.4 billion ) Rio Tinto Finance (USA) Limited and Rio Tinto Finance (USA) plc bonds with maturity dates up to 2042; and US$1.2 billion ( 31 December 2019 : US$1.6 billion ) on the European Debt Issuance Programme. In addition, Rio Tinto Finance plc and Rio Tinto Finance Limited have entered into facility arrangements for an aggregate amount of US$7.5 billion (31 December 2019: US$7.5 billion). The facilities are guaranteed by Rio Tinto plc and Rio Tinto Limited. Rio Tinto plc has provided a guarantee, known as the completion support undertaking (CSU), in favour of the Oyu Tolgoi LLC project finance lenders. At 31 December 2020, US$4.3 billion of project finance debt was outstanding under this facility (2019: US$4.3 billion). Oyu Tolgoi LLC is jointly owned by Erdenes Oyu Tolgoi LLC (34%), which is controlled by the Government of Mongolia, and Turquoise Hill Resources Ltd (66%, of which Rio Tinto owns 51%). The project finance has been raised for development of the underground mine and the CSU will terminate on the completion of the underground mine according to a set of completion tests set out in the project finance facility. The Rio Tinto guarantee applies to the extent that Turquoise Hill Resources Ltd cannot satisfy Oyu Tolgoi LLC’s project finance debt servicing obligations under its own guarantee to the lenders, called the sponsor debt service undertaking (DSU). Both the CSU and DSU contain a carve-out for certain political risk events. Contingent assets The Group has, from time to time, various insurance claims outstanding with reinsurers.

Average number of employees

Average number of employees	12 Months Ended
	Dec. 31, 2020
Number and average number of employees [abstract]
Average number of employees	31 Average number of employees Subsidiaries and joint operations Equity accounted units Group total 2020 2019 2018 2020 2019 2018 2020 2019 2018 Principal locations of employment: Australia and New Zealand 20,482 19,195 19,017 634 619 578 21,116 19,814 19,595 Canada 11,814 11,576 10,620 — — — 11,814 11,576 10,620 UK 172 190 287 — — — 172 190 287 Europe 1,020 959 1,418 — — — 1,020 959 1,418 Africa 2,559 3,121 3,496 1,214 1,250 1,262 3,773 4,371 4,758 US 3,543 3,400 3,792 — — — 3,543 3,400 3,792 Mongolia 3,465 3,215 2,886 — — — 3,465 3,215 2,886 Indonesia — — 1,615 — — — — — 1,615 South America 220 243 210 1,293 1,270 1,289 1,513 1,513 1,499 India 324 272 288 — — — 324 272 288 Singapore 456 430 422 — — — 456 430 422 Other countries (a) 278 267 278 — — — 278 267 278 Total 44,333 42,868 44,329 3,141 3,139 3,129 47,474 46,007 47,458 (a) “Other countries” primarily includes employees in the Middle East (excluding Oman which is included in Africa), and other countries in Asia which are not shown separately in the table above. Employee numbers, which represent the average for the year, include 100% of employees of subsidiary companies. Employee numbers for joint operations and equity accounted units are proportional to the Group’s interest under contractual agreements. Average employee numbers include a part-year effect for companies acquired or disposed of during the year. Part-time employees are included on a full-time-equivalent basis. Temporary employees are included in employee numbers.

Principal subsidiaries

Principal subsidiaries	12 Months Ended
	Dec. 31, 2020
Disclosure of subsidiaries [abstract]
Principal subsidiaries	32 Principal subsidiaries At 31 December 2020 Company and country of incorporation/operation Principal activities Class of shares Proportion of class held (%) Group Non-controlling Australia Argyle Diamonds Limited Mining and processing of diamonds Ordinary 100 100 — Dampier Salt Limited Salt and gypsum production Ordinary 68.36 68.36 31.64 Energy Resources of Australia Ltd (a) Uranium processing Ordinary 86.33 86.33 13.67 Hamersley Iron Pty Limited Iron ore mining Ordinary 100 100 — North Mining Limited (b) Iron ore mining Ordinary 100 100 — Rio Tinto Aluminium (Holdings) Limited Bauxite mining; alumina production; primary aluminium smelting Ordinary 100 100 — Robe River Mining Co Pty Ltd (b) Iron ore mining Class A 40 60 40 Class B 76.36 Brazil Alcan Alumina Ltda. (c) Alumina production and bauxite mining Quota 100 100 — Canada Iron Ore Company of Canada (d) Iron ore mining; iron ore pellets production Common 58.72 58.72 41.28 Rio Tinto Fer et Titane Inc. Titanium dioxide feedstock; high purity iron and steel production Common 100 100 — Class B preference 100 100 — CAD 0.01 preferred 100 100 — Rio Tinto Alcan Inc. Bauxite mining; alumina refining; aluminium smelting Common 100 100 — Diavik Diamond Mines (2012) Inc. (e) Diamond mining and processing Common 100 100 — Guinea Simfer Jersey Limited (f) Iron ore project Ordinary 53 53 47 Madagascar QIT Madagascar Minerals SA (g) Ilmenite mining Common 80 80 15 Investment certificates 100 100 Voting certificates 80 80 20 Mongolia Turquoise Hill Resources Ltd (including Oyu Tolgoi LLC) (h) Copper and gold mining Common 50.79 50.79 49.21 South Africa Richards Bay Titanium (Proprietary) Limited (i) Titanium dioxide; high purity iron production B Ordinary 100 74 26 B preference 100 Parent Preference 100 Richards Bay Mining (Proprietary) Limited (i) Ilmenite, rutile and zircon mining B Ordinary 100 74 26 B preference 100 Parent Preference 100 US Kennecott Holdings Corporation (including Kennecott Utah Copper and Kennecott Exploration) Copper and gold mining, smelting and refining and exploration activities Common US$0.01 100 100 — U.S. Borax Inc. Mining, refining and marketing of borates Common US$0.10 100 100 — This list includes only those companies that have a more significant impact on the profit or operating assets of the Group. Refer to note 44 for a list of related undertakings. 32 Principal subsidiaries continued The Group’s principal subsidiaries are mostly held by intermediate holding companies and not directly by Rio Tinto plc or Rio Tinto Limited. (a) In February 2020, Rio Tinto's interest in Energy Resources of Australia (ERA) increased from 68.4% to 86.3% as a result of new ERA shares issued to Rio Tinto under the Entitlement Offer and Underwriting Agreement to raise funds for the rehabilitation of the Ranger Project Area. (b) Robe River Mining Co Pty Ltd (which is 60% owned by the Group) holds a 30% interest in Robe River Iron Associates (Robe River). North Mining Ltd (which is wholly owned by the Group) holds a 35% interest in Robe River. Through these companies the Group recognises a 65% share of the assets, liabilities, revenues and expenses of Robe River, with a 12% non-controlling interest. The Group therefore has a 53% beneficial interest in Robe River. (c) Alcan Alumina Ltda holds the Group’s 10% interest in Consórcio De Alumínio Do Maranhão, a joint operation in which the Group participates but is not a joint operator. The Group recognises its share of assets, liabilities, revenues and expenses relating to this arrangement. (d) Iron Ore Company of Canada is incorporated in the US, but operates in Canada. (e) Diavik Diamond Mines (2012) Inc. (DDMI) is the legal entity that owns the Group’s 60% interest in the Diavik Joint Venture, an unincorporated arrangement. The Group recognises its share of assets, revenue and expenses relating to this arrangement. Liabilities are recognised according to DDMI’s contractual obligations, with a corresponding 40% receivable or contingent asset representing the co-owner’s share where applicable. (f) Simfer Jersey Limited, a company incorporated in Jersey in which the Group has a 53% interest, has an 85% interest in Simfer S.A., the company that operates the Simandou mining project in Guinea. The Group therefore has a 45.05% indirect interest in Simfer S.A. These entities are consolidated as subsidiaries and together referred to as the Simandou iron ore project. (g) The Group’s shareholding in QIT Madagascar Minerals SA carries an 80% economic interest and 80% of the total voting rights; a further 5% economic interest is held through non-voting investment certificates to give an economic interest of 85%. The non-controlling interests have a 15% economic interest and 20% of the total voting rights. (h) The Group has a 50.79% interest in Turquoise Hill Resources Ltd, which holds a 66% interest in Oyu Tolgoi LLC (OT) which is a subsidiary of Turquoise Hill Resources Ltd. The Group therefore has a 33.5% indirect interest in OT. Turquoise Hill Resources Ltd is incorporated in Canada but operates principally in Mongolia. (i) Additional classes of shares issued by Richards Bay Titanium (Proprietary) Limited and Richards Bay Mining (Proprietary) Limited representing non-controlling interests are not shown. The Group’s total legal and beneficial interest in Richards Bay Titanium (Proprietary) Limited and Richards Bay Mining (Proprietary) Limited is 74% . Summary financial information for subsidiaries that have non-controlling interests that are material to the Group This summarised financial information is shown on a 100% basis. It represents the amounts shown in the subsidiaries’ financial statements prepared in accordance with IFRS under Group accounting policies, including fair value adjustments, and before intercompany eliminations. Income statement summary for the year ended 31 December Iron Ore Company of Canada 2020 US$m Iron Ore Company of Canada 2019 US$m Energy Resources of Australia 2020 US$m Energy Resources of Australia 2019 US$m Turquoise Hill (j)(k)(l) 2020 US$m Turquoise Hill (j)(k)(l) 2019 US$m Revenue 2,269 2,014 162 145 1,078 1,166 Profit/(loss) after tax 611 543 9 5 357 (2,137) – attributable to non-controlling interests 252 224 3 2 130 (1,490) – attributable to Rio Tinto 359 319 5 3 227 (647) Other comprehensive income 56 57 20 2 2 — Total comprehensive income/(loss) 667 600 29 7 359 (2,137) Balance sheet summary as at 31 December 2020 2019 2020 2019 2020 2019 Non-current assets 2,733 2,585 329 76 10,930 9,589 Current assets 670 610 371 258 1,496 2,449 Current liabilities (462) (532) (176) (127) (540) (493) Non-current liabilities (993) (927) (427) (462) (4,404) (4,405) Net assets/(liabilities) 1,948 1,736 97 (255) 7,482 7,140 – attributable to non-controlling interests 804 718 18 — 2,424 2,369 – attributable to Rio Tinto 1,144 1,018 79 (255) 5,058 4,771 Cash flow statement summary for the year ended 31 December 2020 2019 2020 2019 2020 2019 Cash flow from operations 1,027 1,039 (15) (73) 380 298 Dividends paid to non-controlling interests (180) (228) — — — — (j) Turquoise Hill Resources Ltd holds a controlling interest in Oyu Tolgoi LLC (OT). (k) Under the terms of the project finance facility held by OT, there are certain restrictions on the ability of OT to make shareholder distributions. (l) Since 2011, Turquoise Hill has funded common share investments in OT on behalf of Erdenes Oyu Tolgoi LLC (“Erdenes”). In accordance with the Amended and Restated Shareholders Agreement dated 8 June 2011, such funded amounts earn interest at an effective annual rate of LIBOR plus 6.5% and are repayable to them via a pledge over Erdenes’ share of future OT common share dividends. Erdenes also has the right to reduce the outstanding balance by making payments directly to Turquoise Hill. Common share investments funded on behalf of Erdenes, including accrued interest, are recorded as a reduction to the net carrying value of their component of non-controlling interests. As at 31 December 2020, the cumulative amount of such funding was US$1,378 million (31 December 2019: US$1,241 million), excluding accrued interest of US$804 million (31 December 2019: US$655 million) relating to this funding. Income statement summary for the year ended 31 December Robe River Mining Co Pty Robe River Mining Co Pty Other companies and eliminations (m) 2020 US$m Other companies and eliminations (m) 2019 US$m Robe River 2020 US$m Robe River 2019 US$m Revenue 1,738 1,493 2,028 1,743 3,766 3,236 Profit after tax 939 808 1,019 825 1,958 1,633 – attributable to non-controlling interests 376 312 — — 376 312 – attributable to Rio Tinto 563 496 1,019 825 1,582 1,321 Other comprehensive income/(loss) 294 (13) 136 (12) 430 (25) Total comprehensive income 1,233 795 1,155 813 2,388 1,608 Balance sheet summary as at 31 December 2020 2019 2020 2019 2020 2019 Non-current assets 3,452 2,622 4,247 3,687 7,699 6,309 Current assets 865 1,161 2,239 1,873 3,104 3,034 Current liabilities (380) (173) (414) (303) (794) (476) Non-current liabilities (255) (84) (4,752) (3,392) (5,007) (3,476) Net assets 3,682 3,526 1,320 1,865 5,002 5,391 – attributable to non-controlling interests 1,397 1,404 — — 1,397 1,404 – attributable to Rio Tinto 2,285 2,122 1,320 1,865 3,605 3,987 Cash flow statement summary for the year ended 31 December 2020 2019 2020 2019 2020 2019 Cash flow from operations 1,491 1,255 1,771 1,447 3,262 2,702 Dividends paid to non-controlling interests (332) (139) (165) — (497) (139) (m) "Other companies and eliminations” includes North Mining Limited (a wholly owned subsidiary of the Group which accounts for its interest in Robe River) and goodwill of US$383 million (2019: US$349 million) that arose on the Group’s acquisition of its interest in Robe River.

Principal joint operations

Principal joint operations	12 Months Ended
	Dec. 31, 2020
Disclosure of joint operations [abstract]
Principal joint operations	33 Principal joint operations At 31 December 2020 Company and country of incorporation/operation Principal activities Group interest (%) Australia Tomago Aluminium Joint Venture Aluminium smelting 51.6 Gladstone Power Station Power generation 42.1 Hope Downs Joint Venture Iron ore mining 50 Queensland Alumina Limited (a) (b) Alumina production 80 Pilbara Iron Arrangements Infrastructure, corporate and mining services (c) New Zealand New Zealand Aluminium Smelters Limited (a) (b) Aluminium smelting 79.4 Canada Aluminerie Alouette Inc. Aluminium production 40 US Pechiney Reynolds Quebec Inc (b) (d) Aluminium smelting 50.2 This list includes only those joint operations that have a more significant impact on the profit or operating assets of the Group. Refer to note 44 for a list of related undertakings. The Group’s joint operations are held by intermediate holding companies and not directly by Rio Tinto plc or Rio Tinto Limited. (a) Although the Group has a 79.4% interest in New Zealand Aluminium Smelters Limited and an 80% interest in Queensland Alumina Limited, decisions about activities that significantly affect the returns that are generated require agreement of both parties to the arrangements, giving rise to joint control. (b) Queensland Alumina Limited, New Zealand Aluminium Smelters Limited and Pechiney Reynolds Quebec Inc. are joint arrangements that are primarily designed for the provision of output to the parties sharing joint control; this indicates that the parties have rights to substantially all the economic benefits of the assets. The liabilities of the arrangements are in substance satisfied by cash flows received from the parties; this dependence indicates that the parties in effect have obligations for the liabilities. It is these facts and circumstances that give rise to the classification of these entities as joint operations. (c) A number of arrangements are in place between the Australian Iron Ore operations managed by Rio Tinto which allow their respective assets to be operated as a single integrated network across the Pilbara region. The arrangements are managed through two wholly owned subsidiaries: Pilbara Iron (Company) Services Pty Ltd and Pilbara Iron Pty Ltd. In assessing the Pilbara Iron Arrangements, it has been concluded that they collectively constitute a joint operation on the basis that decisions about relevant activities require unanimous consent. The resulting efficiencies are shared between Rio Tinto and Robe River Iron Associates (Robe River), and the parties fund all of the cash flow requirements of Pilbara Iron (Company) Services Pty Ltd and Pilbara Iron Pty Ltd.

Principal joint ventures

Principal joint ventures	12 Months Ended
	Dec. 31, 2020
Disclosure of joint ventures [abstract]
Principal joint ventures	34 Principal joint ventures At 31 December 2020 Company and country of incorporation/operation Principal activities Number of Class of Proportion Group Chile Minera Escondida Ltda (a) Copper mining and refining — — — 30 Oman Sohar Aluminium Co. L.L.C. (b) Aluminium smelting; power generation 37,500 Ordinary 20 20 This list includes only those joint ventures that have a more significant impact on the profit or operating assets of the Group. Refer to note 44 for a list of related undertakings. The Group’s principal joint ventures are held by intermediate holding companies and not directly by Rio Tinto plc or Rio Tinto Limited. (a) Although the Group has a 30% interest in Minera Escondida Ltda, participant and management agreements provide for an Owners’ Council whereby significant commercial and operational decisions about the relevant activities that significantly affect the returns that are generated in effect require the joint approval of both Rio Tinto and BHP Billiton (holders of a 57.5% interest). It is therefore determined that Rio Tinto has joint control. The year end of Minera Escondida Ltda is 30 June. The amounts included in the consolidated financial statements of Rio Tinto are, however, based on accounts of Minera Escondida Limitada that are coterminous with those of the Group. (b) Although the Group holds a 20% interest in Sohar Aluminium Co. L.L.C, decisions about relevant activities that significantly affect the returns that are generated require agreement of all parties to the arrangement. It is therefore determined that Rio Tinto has joint control. Summary information for joint ventures that are material to the Group This summarised financial information is shown on a 100% basis. It represents the amounts shown in the joint ventures’ financial statements prepared in accordance with IFRS under Group accounting policies, including fair value adjustments and amounts due to and from Rio Tinto. Minera Escondida Ltda (c) 2020 US$m Minera Escondida Ltda (c) 2019 US$m Sohar Aluminum Co.L.L.C. (d) 2020 US$m Sohar Aluminum Co.L.L.C. (d) 2019 US$m Revenue 7,650 7,120 640 715 Depreciation and amortisation (1,427) (1,693) (115) (115) Impairment charges (note 6) — — (1,100) — Other operating costs (2,756) (3,670) (430) (505) Operating profit/(loss) 3,467 1,757 (1,005) 95 Finance expense (137) (157) (20) (35) Income tax (1,197) (627) (15) (10) Profit/(loss) after tax 2,133 973 (1,040) 50 Other comprehensive loss (40) (17) — — Total comprehensive income/(loss) 2,093 956 (1,040) 50 Non-current assets 11,833 12,450 1,850 3,045 Current assets 3,107 2,250 270 290 Current liabilities (1,813) (1,827) (675) (205) Non-current liabilities (4,560) (4,670) (200) (845) Net assets 8,567 8,203 1,245 2,285 Assets and liabilities above include: – cash and cash equivalents 1,103 603 30 20 – current financial liabilities (790) (807) (565) (110) – non-current financial liabilities (2,560) (2,380) (30) (675) Dividends received from joint venture (Rio Tinto share) 585 666 — — Reconciliation of the above amounts to the investment recognised in the Group balance sheet Group interest 30% 30% 20% 20% Net assets 8,567 8,203 1,245 2,285 Group’s ownership interest 2,570 2,461 249 457 Carrying value of Group’s interest 2,570 2,461 249 457 (c) In addition to its “Investment in equity accounted units”, the Group recognises deferred tax liabilities of US$358 million (2019: US$362 million) relating to tax on unremitted earnings of equity accounted units. (d) Under covenants stipulated in the agreement to Sohar Aluminium Co. L.L.C.’s secured loan facilities, Sohar Aluminium Co. L.L.C. is currently restricted from making any shareholder distributions until 2021 unless a specified amount of the loan facilities is funded.

Principal associates

Principal associates	12 Months Ended
	Dec. 31, 2020
Disclosure of associates [abstract]
Principal associates	35 Principal associates At 31 December 2020 Company and country of incorporation/operation Principal activities Number of Class of Proportion Group Australia Boyne Smelters Limited (a) Aluminium smelting 153,679,560 Ordinary 59.4 59.4 Brazil Mineração Rio do Norte S.A. (b) Bauxite mining 25,000,000,000 Ordinary 12.5 12 47,000,000,000 Preferred 11.75 US Halco (Mining) Inc. (c) Bauxite mining 4,500 Common 45 45 This list includes only those associates that have a more significant impact on the profit or operating assets of the Group. Refer to note 44 for a list of related undertakings. The Group’s principal associates are held by intermediate holding companies and not directly by Rio Tinto plc or Rio Tinto Limited. (a) The parties that collectively control Boyne Smelters Limited do so through decisions that are determined on an aggregate voting interest that can be achieved by several combinations of the parties. Although each combination requires Rio Tinto’s approval, this is not joint control as defined under IFRS 11. Rio Tinto is therefore determined to have significant influence over this company. (b) Although the Group holds only 12% of Mineração Rio do Norte S.A., it has representation on its board of directors and a consequent ability to participate in the financial and operating policy decisions. It is therefore determined that Rio Tinto has significant influence. (c) Halco (Mining) Inc. has a 51% indirect interest in Compagnie des Bauxites de Guinée, a bauxite mine, the core assets of which are located in Guinea . Summary information for associates that are material to the Group This summarised financial information is shown on a 100% basis. It represents the amounts shown in the associate’s financial statements prepared in accordance with IFRS under Group accounting policies, including fair value adjustments and amounts due to and from Rio Tinto. Boyne Smelters Limited (a) 2020 US$m Boyne Smelters Limited (a) 2019 US$m Revenue — — Loss after tax (b) (198) (7) Other comprehensive income/(loss) (c) 30 (3) Total comprehensive loss (168) (10) Non-current assets 1,037 1,229 Current assets 98 96 Current liabilities (146) (114) Non-current liabilities (779) (814) Net assets 210 397 Reconciliation of the above amount to the investment recognised in the Group balance sheet Group interest 59.4% 59.4% Net assets 210 397 Group's ownership interest 125 236 Loans to equity accounted units 112 113 Carrying value of Group's interest 237 349 (a) Boyne Smelters Limited is a tolling operation; as such it is dependent on its participants for funding which is provided through cash calls. Rio Tinto has made certain prepayments to Boyne for toll processing of alumina. These are charged to Group operating costs as processing takes place. (b) In 2020, includes US$200 million of impairment changes. Refer to note 6. (c) "Other comprehensive income/(loss)” is net of amounts recognised by subsidiaries in relation to quasi equity loans. 35 Principal associates continued Summary information for joint ventures and associates that are not individually material to the Group Associates 2020 US$m Associates 2019 US$m Carrying value of Group's interest 708 704 Profit after tax — 3 Other comprehensive income (5) 10 Total comprehensive income (5) 13 There were no individually material joint ventures in 2019 or 2020.

Purchases and sales of subsidia

Purchases and sales of subsidiaries, joint ventures, associates and other interests in businesses	12 Months Ended
	Dec. 31, 2020
Disclosure Of Purchases And Sales Of Subsidiaries Joint Ventures Associates And Other Interests In Businesses [Abstract]
Purchases and sales of subsidiaries, joint ventures, associates and other interests in businesses	36 Purchases and sales of subsidiaries, joint ventures, associates and other interests in businesses Acquisitions We have made no material acquisitions over the last three years. In 2018, we created a joint venture, ELYSIS, with Alcoa and other partners to develop a carbon-free aluminium smelting process. We treated this as an acquisition and accounted for our interest in ELYSIS using the equity method. We invested cash of US$5 million and contributed patents and licensed intellectual property (IP) to the venture. The patents and IP had no carrying value; however, on formation of the arrangement, they were recorded at fair value to reflect the contributions of the other parties in the joint venture. This value was US$171 million (US$141 million after tax). Disposals We have made no material disposals in 2020. On 16 July 2019 we disposed of our entire 68.62% interest in Rössing Uranium to China National Uranium Corporation Limited for gross cash proceeds of US$6.5 million. After adjusting for cash held on Rössing's balance sheet at the date of disposal and included in the sale, we reported a net cash outflow of US$118 million and recognised a loss on disposal of US$289 million. This includes cumulative currency translation losses of US$212 million recycled from the currency translation reserve on sale of the business. On 1 June 2018 we disposed of our entire 75% interest in the Winchester South coal development project in Queensland, Australia to Whitehaven Coal Limited for US$200 million. This comprised US$150 million cash which was received during 2018 and an unconditional cash payment of US$50 million which was subsequently received in June 2019. Both receipts were recognised within “net cash generated from operating activities” within the cash flow statement. We recognised a gain on disposal of US$195 million within “profit relating to interests in undeveloped projects” in the income statement. On 1 August 2018 we completed the sale of our entire interest in the Hail Creek coal mine (82.0%) and the Valeria coal development project (71.2%) in Queensland, Australia to Glencore for a total consideration of US$1.7 billion. We received net proceeds of US$1,545 million after completion adjustments in respect of the Hail Creek component of this transaction, resulting in a pre-tax gain of US$1,141 million. During 2019 we received a further US$26 million relating to working capital adjustments in respect of this sale. We also received cash proceeds in 2018 of US$170 million in respect of Valeria. Of this amount, US$87 million, relating to the sale of land and investments in associates, was included in investing cash flow, resulting in a pre-tax gain of US$18 million. The remaining US$83 million proceeds were recognised in operating cash flow, resulting in a pre-tax gain of US$83 million in “profit relating to interests in undeveloped projects”. Also on 1 August 2018, we completed the sale of our entire interest in the Kestrel underground coal mine (80.0%) for US$2.25 billion to a consortium comprising EMR Capital (EMR) and PT Adaro Energy Tbk (Adaro). We received net cash proceeds of US$2,270 million, resulting in a pre-tax gain of US$1,010 million. On 14 December 2018 we completed the sale of the Dunkerque aluminium smelter in northern France to Liberty House for US$500 million, subject to final adjustments. In 2018 we received net cash proceeds of US$385 million. We recognised a pre-tax gain on disposal of US$128 million. On 21 December 2018 we sold our interest in the Grasberg mine for US$3.5 billion as part of a series of transactions involving Inalum (PT Indonesia Asahan Aluminium (Persero)) and Freeport-McMoRan Inc. Of the US$3.5 billion received, US$107 million related to our attributable share of copper and gold revenues for 2018, net of our capital contribution for the year. The remaining net proceeds of US$3,392 million were included in investing cash flows and gave rise to a gain on disposal of US$2,146 million. On 1 September 2017, we disposed of our 100% shareholding in Coal & Allied Industries Limited to Yancoal Australia Limited for a total consideration of US$2.69 billion (before working capital adjustments). This comprised US$2.45 billion in cash paid on the closing date and a further US$240 million of unconditional guaranteed royalty payments. Total net cash proceeds received in 2017, net of working capital adjustments, transaction costs and cash transferred, were US$2.54 billion. This included receipt of US$110 million of the unconditional royalty payments. In 2018 we received a further US$90 million of unconditional royalty payments and in 2019 an additional US$20 million. We received US$10 million in 2020 and the final US$10 million was received in early 2021.

Directors' and key management r

Directors' and key management remuneration	12 Months Ended
	Dec. 31, 2020
Disclosure Of Information About Key Management Personnel [Abstract]
Directors' and key management remuneration	37 Directors’ and key management remuneration Aggregate remuneration, calculated in accordance with the UK Companies Act 2006, of the directors of the parent companies was as follows: 2020 US$'000 2019 US$'000 2018 US$'000 Emoluments 6,686 7,524 9,069 Long-term incentive plans 8,974 4,748 2,923 15,660 12,272 11,992 Pension contributions: defined contribution plans 29 42 80 Gains made on exercise of share options — — 107 The Group defines key management personnel as the directors and members of the Executive Committee. The Executive Committee comprises the executive directors, product group chief executive officers and Group executives. Details of the directors and members of the Executive Committee are shown in the Directors' Report on pages 116-119. The aggregate remuneration including pension contributions incurred by Rio Tinto plc in respect of its directors was US$14,983,000 (2019: US$11,565,000; 2018: US$11,465,000). The aggregate pension contribution to defined contribution plans was US$29,000 (2019: US$42,000; 2018: US$80,000). The aggregate remuneration, including pension contributions and other retirement benefits, incurred by Rio Tinto Limited in respect of its directors was US$707,000 (2019: US$749,000; 2018: US$607,000). The aggregate pension contribution to defined contribution plans was US$nil (2019: US$nil; 2018: US$nil). During 2020, no director (2019:nil; 2018:nil), directors accrued retirement benefits under defined benefit arrangements, and two directors (2019: two; 2018: three) accrued retirement benefits under defined contribution arrangements. Emoluments included in the table above have been translated from local currency at the average exchange rate for the year with the exception of bonus payments, which have been translated at the year-end rate. Aggregate compensation, representing the expense recognised under IFRS, as defined in note 1, of the Group’s key management, including directors, was as follows: 2020 US$'000 2019 US$'000 2018 US$'000 Short-term employee benefits and costs 21,685 22,075 23,978 Post-employment benefits 369 477 629 Employment termination benefits 2,789 310 69 Share-based payments 34,954 17,632 14,916 Total 59,797 40,494 39,592 The figures shown above include employment costs which comprise social security and accident premiums in Canada, the UK and US and payroll taxes in Australia paid by the employer as a direct additional cost of hire. In total, they amount to US$2,130,000 (2019: US$2,066,000; 2018: US$2,360,000).

Auditors' remuneration

Auditors' remuneration	12 Months Ended
	Dec. 31, 2020
Auditor's remuneration [abstract]
Auditors' remuneration	38 Auditors’ remuneration Group auditors’ remuneration (a) 2020 US$m 2019 US$m 2018 US$m Audit of the Group 11.0 9.6 9.2 Audit of subsidiaries 6.3 6.8 7.5 Total audit 17.3 16.4 16.7 Audit-related assurance service 0.8 0.8 0.9 Other assurance services (b) 1.4 1.9 3.3 Total assurance services 2.2 2.7 4.2 Tax compliance — 0.1 — Other non-audit services not covered above 0.1 — 0.2 Total non-audit services 2.3 2.8 4.4 Total Group auditors’ remuneration 19.6 19.2 21.1 Audit fees payable to other accounting firms Audit of the financial statements of the Group’s subsidiaries (c) 0.6 1.4 1.4 Fees in respect of pension scheme audits 0.1 0.1 0.1 Total audit fees payable to other accounting firms 0.7 1.5 1.5 (a) In 2020, all amounts were paid to member firms of KPMG. In 2019 and 2018, all amounts were paid to member firms of PwC, being the Group's auditors for these financial years. The remuneration payable to KPMG, the Group auditors, is approved by the Audit Committee. The Committee sets the policy for the award of non-audit work to the auditors and approves the nature and extent of such work, and the amount of the related fees, to ensure that independence is maintained. The fees disclosed above consolidate all payments made to member firms of KPMG by the companies and their subsidiaries, along with fees in respect of joint operations paid for by the Group and includes an estimate of the costs to complete the 2020 audit. Non-audit services arise largely from assurance and/or regulation related work. (b) Other assurance services relates to the review of non-statutory financial information including sustainability reporting. (c) In 2019 and 2018 these amounts include fees payable to KPMG in respect of subsidiaries who's statutory auditor was KPMG prior to their appointment as the Group's auditor.

Related-party transactions

Related-party transactions	12 Months Ended
	Dec. 31, 2020
Related party transactions [abstract]
Related-party transactions	39 Related-party transactions Information about material related-party transactions of the Rio Tinto Group is set out below. Subsidiary companies and joint operations Details of investments in principal subsidiary companies are disclosed in note 32. Information relating to joint operations can be found in note 33. Equity accounted units Transactions and balances with equity accounted units are summarised below. Purchases, trade and other receivables, and trade and other payables relate largely to amounts charged by equity accounted units for toll processing of alumina and purchasing of bauxite and aluminium. Sales relate largely to sales of alumina to equity accounted units for smelting into aluminium. 2020 US$m 2019 US$m 2018 US$m Income statement items Purchases from equity accounted units (960) (1,155) (1,209) Sales to equity accounted units 271 268 493 Cash flow statement items Dividends from equity accounted units 594 669 800 Net funding of equity accounted units (43) (33) (9) Balance sheet items Investments in equity accounted units (a) 15 3,764 3,971 4,299 Loans to equity accounted units 19 41 39 38 Trade and other receivables: amounts due from equity accounted units (b) 18 251 259 278 Trade and other payables: amounts due to equity accounted units 24 (241) (271) (223) (a) Investments in equity accounted units include quasi equity loans. Further information about investments in equity accounted units is set out in not es 34 and 35. (b) This includes prepayments of tolling charges. Pension funds Information relating to pension fund arrangements is set out in note 42.

Exchange rates in US$

Exchange rates in US$	12 Months Ended
	Dec. 31, 2020
Foreign exchange rates [abstract]
Exchange rates in US$	40 Exchange rates in US$ The principal exchange rates used in the preparation of the 2020 financial statements were: Full-year average Year-end 2020 2019 2018 2020 2019 2018 Sterling 1.28 1.28 1.34 1.36 1.31 1.27 Australian dollar 0.69 0.70 0.75 0.77 0.70 0.70 Canadian dollar 0.75 0.75 0.77 0.78 0.77 0.73 Euro 1.14 1.12 1.18 1.23 1.12 1.14 South African rand 0.061 0.069 0.076 0.068 0.071 0.069

Share-based payments

Share-based payments	12 Months Ended
	Dec. 31, 2020
Disclosure of terms and conditions of share-based payment arrangement [abstract]
Share-based payments	41 Share-based payments Rio Tinto plc and Rio Tinto Limited have a number of share-based incentive plans. These plans have been accounted for in accordance with the fair value recognition provisions of IFRS 2 “Share-based Payment”. The charge that has been recognised in the income statement for Rio Tinto’s share-based incentive plans, and the related liability (for cash-settled awards), is set out in the table below. Charge recognised for the year Liability at the end of the year 2020 US$m 2019 US$m 2018 US$m 2020 US$m 2019 US$m Equity-settled awards 131 118 118 — — Cash-settled awards 7 5 4 7 19 Total 138 123 122 7 19 The main Rio Tinto plc and Rio Tinto Limited plans are as follows: UK Share Plan (formerly the Share Ownership Plan) The fair values of Matching and Free Shares made by Rio Tinto plc are taken to be the market value of the shares on the date of purchase. These awards are settled in equity. Equity Incentive Plan In 2018, shareholders approved the introduction of the Rio Tinto 2018 Equity Incentive Plan (the “EIP”). From 2018, all long-term incentive awards have been granted under this umbrella plan which allows for awards in the form of Performance Share Awards (PSA), Management Share Awards (MSA) and Bonus Deferral Awards (BDA) to be granted. Performance Share Awards (Performance Share Plans prior to 2018) Participants are generally assigned shares in settlement of their PSA on vesting and therefore the awards are accounted for in accordance with the requirements applying to equity-settled share-based payment transactions, including the dividends accumulated from date of award to vesting. For the parts of awards with Total Shareholder Return (TSR) performance conditions, the fair value of the awards is calculated using a Monte Carlo simulation model taking into account the TSR performance conditions. One third of the awards granted up to 2017 (inclusive) are subject to an earnings margin performance target relative to ten global mining comparators. As this is a non-market related performance condition, under IFRS 2, the fair value recognised is reviewed at each accounting date based on the directors’ expectations for the proportion vesting. Forfeitures prior to vesting are assumed at 5% per annum of outstanding awards (2019: 5% per annum). For grants made from 2018, the earnings margin performance target applying to the PSA was removed and instead all of the awards are subject to the TSR performance conditions. Management Share Awards (Management Share Plans prior to 2018) The vesting of these awards is dependent on service conditions being met; no performance conditions apply. In general, the awards will be settled in equity, including the dividends accumulated from date of award to vesting and therefore the awards are accounted for in accordance with the requirements applying to equity-settled share-based payment transactions. The fair value of each award on the day of grant is equal to the share price on the day of grant. Forfeitures prior to vesting are assumed at 7% per annum of outstanding awards (2019: 7% per annum). 41 Share-based payments continued Bonus Deferral Awards (Bonus Deferral Plans prior to 2018) Bonus Deferral Awards (BDA) provide for the mandatory deferral of 50% of the bonuses for executive directors and Executive Committee members and 25% of the bonuses for other executives. The vesting of these awards is dependent only on service conditions being met. In general, the awards will be settled in equity including the dividends accumulated from date of award to vesting and therefore the awards are accounted for in accordance with the requirements applying to equity-settled share-based payment transactions. The fair value of each award on the day of grant is equal to the share price on the day of grant. Forfeitures prior to vesting are assumed at 3% per annum of outstanding awards (2019: 3% per annum). Global Employee Share Plans The Global Employee Share Plans were introduced in 2012. Under these Plans, the companies provide a matching share award for each investment share purchased by a participant. The vesting of these matching awards is dependent on service conditions being met and the continued holding of investment shares by the participant until vesting. These awards are settled in equity including the dividends accumulated from date of award to vesting. The fair value of each matching share on the day of grant is equal to the share price on the date of purchase less a deduction of 15% for cancellations (caused by employees electing to withdraw their investment shares before vesting of their matching shares). Forfeitures prior to vesting are assumed at 5% per annum of outstanding awards (2019: 5% per annum). The Management Share Awards, Performance Share Awards, Bonus Deferral Awards, Equity Incentive Plan, Global Employee Share Plans and UK Share Plan together represent 100% (2019: 100%) of the total IFRS 2 charge for Rio Tinto plc and Rio Tinto Limited plans in 2020. Performance Share Awards (granted under either the Performance Share Plans or the Equity Incentive Plans) Rio Tinto plc awards Rio Tinto Limited awards 2020 number Weighted average fair value at grant date 2020 £ 2019 number Weighted average fair value at grant date 2019 £ 2020 number Weighted average fair value at grant date 2020 A$ 2019 number Weighted average fair value at grant date 2019 A$ Unvested awards at 1 January 3,803,394 22.20 3,845,082 21.86 1,636,517 45.11 1,797,279 43.34 Awarded 716,111 13.55 755,735 24.68 198,863 33.56 297,189 54.55 Forfeited (136,030) 21.13 (122,961) 23.95 (178,921) 46.37 (126,775) 44.02 Failed performance conditions (145,661) 16.64 (384,130) 23.79 (63,852) 33.38 (188,956) 46.42 Vested (459,773) 20.55 (290,332) 21.36 (201,234) 41.21 (142,220) 41.72 Unvested awards at 31 December 3,778,041 21.01 3,803,394 22.20 1,391,373 44.40 1,636,517 45.11 Rio Tinto plc awards Rio Tinto Limited awards 2020 number Weighted average fair value at grant date 2020 £ 2019 number Weighted average fair value at grant date 2019 £ 2020 number Weighted average fair value at grant date 2020 A$ 2019 number Weighted average fair value at grant date 2019 A$ Vested awards settled in shares during the year (including dividend shares applied on vesting) 476,602 43.13 339,821 45.52 217,287 93.48 151,607 100.30 Vested awards settled in cash during the year (including dividend shares applied on vesting) 108,887 43.13 1,279 43.65 28,208 93.82 1,347 92.97 In addition to the equity-settled awards shown above, there were 48,191 Rio Tinto plc and 15,164 Rio Tinto Limited cash-settled awards outstanding at 31 December 2020 (2019: 49,019 Rio Tinto plc and 276,722 Rio Tinto Limited cash-settled awards outstanding). The total liability for these awards at 31 December 2020 was US$3 million (2019: US$13 million). Management Share Awards, Bonus Deferral Awards (granted under the Management Share Plans, Bonus Deferral Plans or Equity Incentive Plans), Global Employee Share Plans and UK Share Plan (combined) Rio Tinto plc awards (a) Rio Tinto Limited awards 2020 number Weighted average fair value at grant date 2020 £ 2019 number Weighted average fair value at grant date 2019 £ 2020 number Weighted average fair value at grant date 2020 A$ 2019 number Weighted average fair value at grant date 2019 A$ Unvested awards at 1 January (b) 2,613,013 37.14 3,042,020 31.43 2,273,669 75.46 2,613,930 61.71 Awarded 1,190,528 36.27 1,043,817 40.41 921,070 83.20 846,008 86.56 Forfeited (99,038) 44.42 (224,402) 39.46 (60,935) 85.01 (174,025) 72.18 Cancelled (33,955) 37.72 (24,043) 32.87 (50,354) 71.45 (35,481) 60.91 Vested (1,019,687) 34.46 (1,224,379) 25.40 (866,716) 65.19 (976,763) 49.39 Unvested awards at 31 December (b) 2,650,861 37.50 2,613,013 37.14 2,216,734 82.52 2,273,669 75.46 Comprising: – Management Share Awards 1,352,759 38.73 1,398,039 38.68 1,291,203 85.80 1,363,601 78.67 – Bonus Deferral Awards 211,905 36.14 192,878 41.95 53,324 85.53 87,930 87.81 – Global Employee Share Plan 1,050,608 36.06 982,932 33.98 872,207 77.47 822,138 68.82 – UK Share Plan 35,589 41.54 39,164 37.86 — — — — 2020 number Weighted average fair value at grant date 2020 £ 2019 number Weighted average fair value at grant date 2019 £ 2020 number Weighted average fair value at grant date 2020 A$ 2019 number Weighted average fair value at grant date 2019 A$ Vested awards settled in shares during the year (including dividend shares applied on vesting): – Management Share Awards 707,133 42.26 681,242 43.68 640,948 97.74 582,948 93.05 – Bonus Deferral Awards 111,233 49.71 163,076 42.53 63,404 101.96 85,142 97.30 – Global Employee Share Plan 401,169 43.82 543,426 43.04 299,381 98.60 421,614 91.50 – UK Share Plan 2,392 45.73 34,196 42.21 — — — — Vested awards settled in cash during the year (including dividend shares applied on vesting): – Bonus Deferral Awards 19,617 48.34 — — — — — — (a) Awards of Rio Tinto American Depository Receipts (ADRs) under the Global Employee Share Plan are included within the totals for Rio Tinto plc awards for the purpose of these tables. (b) These numbers are presented and calculated in accordance with IFRS 2 and represent awards for which an IFRS 2 charge continues to be accrued for. In addition to the equity-settled awards shown above, there were 89,253 Rio Tinto plc and 14,878 Rio Tinto Limited cash-settled awards outstanding at 31 December 2020 (2019: 52,881 Rio Tinto plc and 81,050 Rio Tinto Limited cash-settled awards outstanding). The total liability for these awards at 31 December 2020 was US$4 million (2019: US$6 million).

Post-retirement benefits

Post-retirement benefits	12 Months Ended
	Dec. 31, 2020
Disclosure of information about defined benefit plans [abstract]
Post-retirement benefits	42 Post-retirement benefits Description of plans The Group operates a number of pension and post-retirement healthcare plans around the world. Some of these plans are defined contribution and some are defined benefit, with assets held in separate trusts, foundations and similar entities. Defined benefit pension and post-retirement healthcare plans expose the Group to a number of risks: Uncertainty in benefit payments The value of the Group’s liabilities for post-retirement benefits will ultimately depend on the amount of benefits paid out. This in turn will depend on the level of future pay increases, the level of inflation (for those benefits that are subject to some form of inflation protection) and how long individuals live. Volatility in asset values The Group is exposed to future movements in the values of assets held in pension plans to meet future benefit payments. Uncertainty in cash funding Movements in the values of the obligations or assets may result in the Group being required to provide higher levels of cash funding, although changes in the level of cash required can often be spread over a number of years. In some countries control over the rate of cash funding or over the investment policy for pension assets might rest to some extent with a trustee body or other body that is not under the Group’s direct control. In addition the Group is also exposed to adverse changes in pension regulation. For these reasons the Group has a policy of moving away from defined benefit pension provisions and towards defined contribution arrangements instead. The defined benefit pension plans for salaried employees are closed to new entrants in almost all countries. For unionised employees, some plans remain open. The Group does not usually participate in multi-employer plans in which the risks are shared with other companies using those plans. The Group’s participation in such plans is immaterial and consequently no detailed disclosures are provided in this note. Pension plans The majority of the Group’s defined benefit pension obligations are in Canada, the UK, the US and Switzerland. In Canada the benefits for salaried staff are generally linked to final average pay and the plans are generally closed to new entrants. Benefits for bargaining employees are reviewed in negotiation with unions and are typically linked either to final average pay or to a flat monetary amount per year of service. New employees join arrangements which are defined contribution from the Group’s perspective, with any required additional funding being provided by employees. The plans are subject to the regulatory requirements that apply to Canadian pension plans in the relevant provinces and territories (predominantly Quebec). Pension Committees are responsible for ensuring that the plans operate in a manner that is compliant with the relevant regulations. The Pension Committees generally have a number of members appointed by the sponsor and a number appointed by the plan participants. In some cases there is also an independent Committee member. The defined benefit sections of the UK arrangements are linked to final pay. New employees are admitted to defined contribution sections. The plans are subject to the regulatory requirements that apply to UK pension plans. Trustees are responsible for ensuring that the plans operate in a manner that is compliant with UK regulations. The trustee board governing the main UK plans has a number of directors appointed by the sponsor, a number appointed by the plan participants and an independent trustee director. A number of defined benefit pension plans are sponsored by the US entities. Benefits for salaried staff are generally linked to final average pay. Benefits for bargaining employees are reviewed in negotiation with unions and are typically a flat monetary amount per year of service. New employees are admitted to defined contribution plans. A Benefits Governance Committee is responsible for ensuring that the plans are compliant with US regulations. Members of that Committee are appointed by the sponsor. In Europe, there are defined benefit plans in Switzerland, Germany and France. The largest single plan is in Switzerland, which provides benefits linked to final average pay. The Swiss plan is overseen by a foundation board which is responsible for ensuring that the plan complies with Swiss regulations. Foundation board members are appointed by the plan sponsor, by employees and by retirees. In Australia, the main arrangements are principally defined contribution in nature but there are sections providing defined benefits linked to final pay, typically paid in lump sum form. These arrangements are managed by an independent financial institution. Rio Tinto may nominate candidates to be considered for appointment to the governing board, as may other employers. One third of the board positions are nominated by employers, with the remaining positions being filled by independent directors and directors nominated by participants. The Group also operates a number of unfunded defined benefit plans, which are included in the figures below. Post-retirement healthcare plans Certain subsidiaries of the Group, mainly in the US and Canada, provide health and life insurance benefits to retired employees and in some cases to their beneficiaries and covered dependants. Eligibility for cover is dependent upon certain age and service criteria. These arrangements are generally unfunded, and are included in the figures below. Plan assets The assets of the pension plans are invested predominantly in a diversified range of equities, bonds and property. Consequently, the funding level of the pension plans is affected by movements in the level of equity markets and also by movements in interest rates. The Group monitors its exposure to changes in interest rates and equity markets and also measures its balance sheet pension risk using a value at risk approach. These measures are considered when deciding whether significant changes in investment strategy are required. Investment strategy reviews are conducted on a periodic basis for the main pension plans to determine the optimal investment mix bearing in mind the Group’s tolerance for risk, the risk tolerance of the local sponsor companies and the views of the Pension Committees and trustee boards who are legally responsible for the investments of the plans. The assets of the pension plans may also be invested in Qualifying Insurance Policies which provide a stream of payments to match the benefits being paid out by the plans, thereby removing investment, inflation and longevity risks. In Canada, the UK and Switzerland, the Group works with the governing bodies to ensure that the investment policy adopted is consistent with the Group’s tolerance for risk. In the US the Group has direct control over the investment policy, subject to local investment regulations. The proportions of the total fair value of assets in the pension plans for each asset class at the balance sheet date were: 2020 2019 Equities 21.1 % 20.4 % – Quoted 17.9 % 17.0 % – Private 3.2 % 3.4 % Bonds 55.8 % 63.4 % – Government fixed income 17.7 % 18.4 % – Government inflation-linked 9.6 % 16.2 % – Corporate and other publicly quoted 22.6 % 24.1 % – Private 5.9 % 4.7 % Property 7.5 % 8.8 % – Quoted property funds 3.1 % 3.4 % – Unquoted property funds 4.4 % 5.4 % Qualifying insurance policies 11.3 % 3.1 % Cash & other 4.3 % 4.3 % Total 100.0 % 100.0 % The assets of the plans are managed on a day-to-day basis by external specialist fund managers. These managers may invest in the Group’s securities subject to limits imposed by the relevant fiduciary committees and local legislation. The approximate total holding of Group securities within the plans is US$4 million (2019: US$3 million). The holdings of quoted equities are invested either in pooled funds or segregated accounts held in the name of the relevant pension funds. These equity portfolios are well diversified in terms of the geographic distribution and market sectors. The holdings of government bonds are generally invested in the debt of the country in which a pension plan is situated. Corporate and other quoted bonds are usually of investment grade. Private debt is mainly held in the North American and UK pension funds and is invested in North American and European companies. The property funds are invested in a diversified range of properties. The holdings of cash & other are predominantly cash and short-term money market instruments. Investments in private equity, private debt and property are less liquid than the other investment classes listed above and therefore the Group’s investment in those asset classes is restricted to a level that does not endanger the liquidity of the pension plans. Qualifying insurance policies are held with insurance companies that are regulated by the relevant local authorities. The value of those policies is calculated by the local actuaries using assumptions consistent with those adopted for valuing the insured obligations. The significant increase in the allocation to Qualifying insurance policies during 2020 results from an insurance transaction completed by one of the UK pension plans. The purchase price was financed predominantly from that plan’s inflation-linked government bonds. The Group makes limited use of futures, repurchase agreements and other instruments to manage the interest rate risk in some of its plans. Fund managers may also use derivatives to hedge currency movements within their portfolios and, in the case of bond managers, to take positions that could be taken using direct holdings of bonds but more efficiently. Maturity of defined benefit obligations An approximate analysis of the maturity of the obligations is given in the table below: Pension Other 2020 Total 2019 Total 2018 Total Proportion relating to current employees 21 % 19 % 21 % 20 % 19 % Proportion relating to former employees not yet retired 12 % 0 % 11 % 12 % 11 % Proportion relating to retirees 67 % 81 % 68 % 68 % 70 % Total 100 % 100 % 100 % 100 % 100 % Average duration of obligations (years) 14.4 13.5 14.3 14.4 13.4 Geographical distribution of defined benefit obligations An approximate analysis of the geographic distribution of the obligations is given in the table below: Pension Other 2020 Total 2019 Total 2018 Total Canada 54 % 46 % 53 % 53 % 48 % UK 30 % 2 % 28 % 28 % 28 % US 7 % 50 % 10 % 10 % 14 % Switzerland 5 % 0 % 5 % 5 % 5 % Other 4 % 2 % 4 % 4 % 5 % Total 100 % 100 % 100 % 100 % 100 % 42 Post-retirement benefits continued Total expense recognised in the income statement Pension Other 2020 Total US$m 2019 Total US$m 2018 Total US$m Current employer service cost for defined benefit plans (131) (6) (137) (125) (165) Past service cost (2) — (2) — (36) Curtailment gains — — — — 2 Settlement (losses)/gains (1) — (1) 51 5 Net interest on net defined benefit liability (22) (27) (49) (58) (79) Non-investment expenses paid from the plans (16) — (16) (14) (15) Total defined benefit expense (172) (33) (205) (146) (288) Current employer service cost for defined contribution and industry-wide plans (262) (2) (264) (238) (244) Total expense recognised in the income statement (434) (35) (469) (384) (532) The above expense amounts are included as an employee cost within net operating costs. No amounts have been excluded from underlying earnings in 2020, 2019 or 2018. The settlement gains in 2019 and 2018 were the result of certain US obligations being transferred to external insurance companies and of certain US obligations being settled through a lump sum window exercise being offered to members with a deferred pension. The past service cost in 2018 related primarily to benefit amendments in the US and also included US$9 million to reflect the estimated cost of equalising benefits in the Group's UK schemes, in line with the requirements of the court judgment on 26 October 2018 in the case involving Lloyds Banking Group and relating to Guaranteed Minimum Pensions. A past service cost of US$1 million was recognised in 2020 in relation to the subsequent court judgment addressing the need to equalise historical transfer values. Total amount recognised in other comprehensive income before tax 2020 US$m 2019 US$m 2018 US$m Actuarial (losses)/gains (1,242) (1,295) 1,382 Return on assets, net of interest on assets 768 1,033 (527) Gain on application of asset ceiling — — 52 Total (loss)/gain recognised in other comprehensive income (474) (262) 907 Amounts recognised in the balance sheet The following amounts were measured in accordance with IAS 19 at 31 December: Pension Other 2020 Total US$m 2019 Total US$m Total fair value of plan assets 14,905 — 14,905 13,923 Present value of obligations – funded (15,731) — (15,731) (14,311) Present value of obligations – unfunded (479) (968) (1,447) (1,342) Present value of obligations – total (16,210) (968) (17,178) (15,653) Net deficit to be shown in the balance sheet (1,305) (968) (2,273) (1,730) Comprising: – Deficits (2,087) (968) (3,055) (2,714) – Surpluses 782 — 782 984 Net deficits on pension plans (1,305) — (1,305) (831) Unfunded post-retirement healthcare obligation — (968) (968) (899) The surplus amounts shown above are included in the balance sheet as "Receivables and other assets". See note 18. Deficits are shown in the balance sheet within "Provisions (including post-retirement benefits)". See note 25. Funding policy and contributions to plans The Group reviews the funding position of its major pension plans on a regular basis and considers whether to provide funding above the minimum level required in each country. In Canada and the US the minimum level is prescribed by legislation. In the UK and Switzerland the minimum level is negotiated with the local trustee or foundation in accordance with the funding guidance issued by the local regulators. In deciding whether to provide funding above the minimum level the Group takes into account other possible uses of cash within the Group, the tax situation of the local sponsoring entity and any strategic advantage that the Group might obtain by accelerating contributions. The Group does not generally pre-fund post-retirement healthcare arrangements. Pension Other 2020 Total US$m 2019 Total US$m 2018 Total US$m Contributions to defined benefit plans 169 32 201 257 248 Contributions to defined contribution plans 259 2 261 235 244 Total 428 34 462 492 492 The level of surplus in the Rio Tinto Pension Fund in the UK is such that it may be used to pay for the employer contributions to the defined contribution section of that Fund, in accordance with the funding arrangements agreed with the Trustee of that Fund. Consequently, the cash paid to defined contribution plans is lower than the defined contribution service cost by US$3 million. Contributions to defined benefit pension plans are kept under regular review and actual contributions will be determined in line with the Group’s wider financing strategy, taking into account relevant minimum funding requirements. As contributions to many plans are reviewed on at least an annual basis, the contributions for 2021 and subsequent years cannot be determined precisely in advance. Most of the Group’s largest pension funds are fully funded on their local funding basis and do not require long-term funding commitments at present. Contributions to defined benefit pension plans for 2021 are estimated to be around US$150 million but may be higher or lower than this depending on the evolution of financial markets and voluntary funding decisions taken by the Group. Contributions for subsequent years are expected to be at similar levels. Healthcare plans are generally unfunded and contributions for future years will be equal to benefit payments net of participant contributions. The Group’s contributions in 2021 are expected to be similar to the amounts paid in 2020. Movements in the net defined benefit liability A summary of the movement in the net defined benefit liability is shown in the first table below. The subsequent tables provide a more detailed analysis of the movements in the present value of the obligations and the fair value of assets. Pension Other 2020 Total US$m 2019 Total US$m Change in the net defined benefit liability Net defined benefit liability at the start of the year (831) (899) (1,730) (1,551) Amounts recognised in income statement (172) (33) (205) (146) Amounts recognised in other comprehensive income (416) (58) (474) (262) Employer contributions 169 32 201 257 Arrangements added/divested — — — (5) Assets transferred to defined contribution section (3) — (3) (3) Currency exchange rate (loss) (52) (10) (62) (20) Net defined benefit liability at the end of the year (1,305) (968) (2,273) (1,730) Pension Other 2020 Total US$m 2019 Total US$m Change in present value of obligation Present value of obligation at the start of the year (14,754) (899) (15,653) (14,754) Current employer service costs (131) (6) (137) (125) Past service cost (2) — (2) — Settlements 6 — 6 638 Interest on obligation (357) (27) (384) (476) Contributions by plan participants (22) — (22) (23) Benefits paid 746 32 778 862 Experience gains 46 15 61 111 Changes in financial assumptions (loss) (1,357) (85) (1,442) (1,447) Changes in demographic assumptions gain 127 12 139 41 Arrangements (added) — — — (5) Currency exchange rate (loss) (512) (10) (522) (475) Present value of obligation at the end of the year (16,210) (968) (17,178) (15,653) 42 Post-retirement benefits continued Pension Other 2020 Total US$m 2019 Total US$m Change in plan assets Fair value of plan assets at the start of the year 13,923 — 13,923 13,203 Settlements (7) — (7) (587) Interest on assets 335 — 335 418 Contributions by plan participants 22 — 22 23 Contributions by employer 169 32 201 257 Benefits paid (746) (32) (778) (862) Non-investment expenses (16) — (16) (14) Return on plan assets, net of interest on assets 768 — 768 1,033 Assets transferred to defined contribution section (3) — (3) (3) Currency exchange rate gain 460 — 460 455 Fair value of plan assets at the end of the year 14,905 — 14,905 13,923 Most of the settlement amounts shown above relate to the US, where assets and obligations for some pensions in payment were transferred to insurance companies. Obligations were also settled through a lump sum window exercise being offered to members with a deferred pension in the US. The asset ceiling had no effect during the year. In determining the extent to which the asset ceiling has an effect, the Group considers the funding legislation in each country and the rules specific to each pension plan. The calculation takes into account any minimum funding requirements that may be applicable to the plan, whether any reduction in future Group contributions is available, and whether a refund of surplus may be available. In considering whether any refund of surplus is available the Group considers the powers of trustee boards and similar bodies to augment benefits or wind up a plan. Where such powers are unilateral, the Group does not consider a refund to be available at the end of the life of a plan. Where the plan rules and legislation both permit the employer to take a refund of surplus, the asset ceiling may have no effect, although it may be the case that a refund will only be available many years in the future. Main assumptions (rates per annum) The main assumptions for the valuations of the plans under IAS 19 are set out below. Where there are multiple plans in a country the rates below are weighted-average figures. Canada UK US Switzerland At 31 December 2020 Discount rate 2.5 % 1.2 % 2.2 % 0.1 % Inflation (a) 1.6 % 2.9 % 2.1 % 0.9 % Rate of increase in pensions 0.1 % 2.5 % — % 0.5 % Rate of increase in salaries 2.8 % 3.6 % 3.6 % 1.9 % At 31 December 2019 Discount rate 3.1 % 2.0 % 3.1 % 0.2 % Inflation (a) 1.6 % 2.9 % 2.0 % 1.1 % Rate of increase in pensions 0.1 % 2.5 % — % 0.2 % Rate of increase in salaries 2.8 % 3.5 % 3.5 % 2.1 % (a) The inflation assumption shown for the UK is for the Retail Price Index. The assumption for the Consumer Price Index at 31 December 2020 was 2.1% (2019: 2.0%). The main financial assumptions used for the healthcare plans, which are predominantly in the US and Canada, were: discount rate: 2.5% (2019: 3.3%); medical trend rate: 6.3% reducing to 4.6% by the year 2031 broadly on a straight line basis (2019: 6.1%, reducing to 4.6% by the year 2029); claims costs based on individual company experience. For both the pension and healthcare arrangements the post-retirement mortality assumptions allow for future improvements in longevity. The mortality tables used imply that a man aged 60 at the balance sheet date has a weighted average expected future lifetime of 27 years (2019: 27 years) and that a man aged 60 in 2040 would have a weighted average expected future lifetime of 28 years (2019: 28 years).The mortality tables are generally based upon the latest standard tables published in each country, adjusted appropriately to reflect the actual mortality experience of the plan participants where credible data is available.. Sensitivity The values reported for the defined benefit obligations are sensitive to the actuarial assumptions used for projecting future benefit payments and discounting those payments. In order to estimate the sensitivity of the obligations to changes in assumptions, we calculate what the obligations would be if we were to make changes to each of the key assumptions in isolation. The difference between this figure and the figure calculated using our stated assumptions is an indication of the sensitivity to changes in each assumption. The results of this sensitivity analysis are summarised in the table below. Note that this approach is valid for small changes in the assumptions but will be less accurate for larger changes in the assumptions. The sensitivity to inflation includes the impact on pension increases, which are generally linked to inflation where they are granted. 2020 2019 Approximate Approximate Assumption Change in assumption Pensions Other Pensions Other Discount rate Increase of 0.5 percentage points 988 62 894 56 Decrease of 0.5 percentage points (1,186) (66) (1,057) (60) Inflation Increase of 0.5 percentage points (484) (19) (447) (17) Decrease of 0.5 percentage points 450 17 422 15 Salary increases Increase of 0.5 percentage points (81) (1) (55) (1) Decrease of 0.5 percentage points 72 1 54 1 Demographic – allowance for future improvements in longevity Participants assumed to have the mortality rates of individuals who are one year older 520 19 443 18 Participants assumed to have the mortality rates of individuals who are one year younger (562) (19) (465) (18)

Events after the balance sheet

Events after the balance sheet date	12 Months Ended
	Dec. 31, 2020
Disclosure of non-adjusting events after reporting period [abstract]
Events after the balance sheet date	45 Events after the balance sheet date Amended tax assessments On 2 March 2021, the Australian Taxation Office (ATO) has issued Rio Tinto Limited with amended assessments of A$359.4 million (US$279.8 million) primary tax and A$47.1 million (US$36.7 million) of interest. This is in addition to the more than A$8.4 billion (US$6.4 billion) of Australian income tax paid during the relevant period. The assessments relate to the denial of interest deductions on an isolated borrowing used to pay an intragroup dividend in 2015. This borrowing was repaid in 2018. Borrowing to fund the payment of a dividend is a normal commercial practice. Rio Tinto is confident of its position and will dispute the assessments. In accordance with the usual practice Rio Tinto will pay 50% of the primary tax up-front as part of the objections process. No adjustment has been made to our balance sheet at 31 December 2020 following receipt of these amended assessments. Resolution copper project On 15 January 2021, we announced that the Resolution Copper project had entered the next phase of public consultation in the ongoing permitting process, led by the US Forest Service, with the release of its independent Final Environmental Impact Statement (FEIS). On 1 March 2021, the US Department of Agriculture directed the Forest Service to withdraw the Notice of Availability to provide additional time to consider the significant input received from many parties after the release of the FEIS. Management is evaluating the Forest Service's decision to rescind the FEIS and draft Record of Decision. In the meantime, we will continue to engage in the process determined by the US government and are committed to ongoing consultation with Native American Tribes and local communities.

Rio Tinto financial information

Rio Tinto financial information by business unit	12 Months Ended
	Dec. 31, 2020
Disclosure Of Financial Information By Business Unit [Abstract]
Rio Tinto financial information by business unit	Gross revenue (a) for the year ended 31 December Underlying EBITDA (b) for the year ended 31 December Net earnings (c) for the year ended 31 December Rio Tinto 2020 US$m 2019 US$m 2018 US$m 2020 US$m 2019 US$m 2018 US$m 2020 US$m 2019 US$m 2018 US$m Iron Ore Pilbara (d) 27,027 23,681 18,359 18,896 15,936 11,267 11,551 9,619 6,460 Dampier Salt 68.4 252 271 246 43 75 56 12 27 18 Evaluation projects/other (e) 657 123 126 (32) 87 55 (112) (8) 53 Intra-segment (e) (428) — — (70) — — (53) — — Total Iron Ore 27,508 24,075 18,731 18,837 16,098 11,378 11,398 9,638 6,531 Aluminium (f) Bauxite 2,302 2,490 2,364 943 1,045 852 434 498 466 Alumina 2,233 2,720 3,423 262 567 808 92 247 390 Primary Metal 4,489 4,940 6,468 904 755 1,418 169 40 595 Pacific Aluminium 1,944 2,204 2,541 112 (22) 148 (6) (137) — Intra-segment and other (2,510) (3,079) (4,084) 6 30 (92) (159) 21 (69) Integrated operations 8,458 9,275 10,712 2,227 2,375 3,134 530 669 1,382 Other product group items 856 1,065 1,479 7 16 17 (5) 10 11 Product group operations 9,314 10,340 12,191 2,234 2,391 3,151 525 679 1,393 Evaluation projects/other — — — (82) (106) (56) (54) (80) (46) Total Aluminium 9,314 10,340 12,191 2,152 2,285 3,095 471 599 1,347 Copper & Diamonds Rio Tinto Kennecott 100.0 1,529 1,879 1,862 588 843 785 149 397 293 Escondida 30.0 2,296 2,136 2,274 1,462 1,034 1,301 650 325 506 Grasberg joint venture (h) — — 457 — — 281 — — 217 Oyu Tolgoi and Turquoise Hill (i) 1,078 1,166 1,180 390 357 375 160 25 69 Diamonds (j) 459 619 695 83 151 301 9 (21) 118 Product group operations 5,362 5,800 6,468 2,523 2,385 3,043 968 726 1,203 Evaluation projects/other 66 15 — (351) (312) (267) (205) (172) (149) Total Copper & Diamonds 5,428 5,815 6,468 2,172 2,073 2,776 763 554 1,054 Energy & Minerals Rio Tinto Coal Australia (k) — — 989 — — 893 — — 591 Iron Ore Company of Canada 58.7 2,444 2,189 1,583 1,130 1,024 586 383 332 166 Rio Tinto Iron & Titanium (l) 1,651 1,938 1,782 476 611 510 216 254 174 Rio Tinto Borates 100.0 564 593 622 126 180 197 65 96 111 Uranium (m) 303 375 415 24 55 18 6 25 (4) Product group operations 4,962 5,095 5,391 1,756 1,870 2,204 670 707 1,038 Simandou iron ore project (n) — — — (14) (12) (15) (6) (5) (7) Evaluation projects/other 52 55 60 (96) (96) (49) (87) (91) (36) Total Energy & Minerals 5,014 5,150 5,451 1,646 1,762 2,140 577 611 995 Other operations (o) 18 18 9 — (77) (70) (54) (89) (102) Inter-segment transactions (264) (31) (15) (94) (9) — (32) (3) — Product group total 47,018 45,367 42,835 24,713 22,132 19,319 13,123 11,310 9,825 Central pension costs, share-based payments and insurance 72 59 (128) 81 60 (90) Restructuring, project and one-off costs (133) (183) (272) (108) (94) (190) Central costs (500) (496) (552) (418) (550) (410) Exploration and evaluation (250) (315) (231) (216) (231) (193) Net interest (14) (122) (134) Underlying EBITDA/earnings 23,902 21,197 18,136 12,448 10,373 8,808 Items excluded from underlying EBITDA/earnings (395) (722) 5,127 (2,679) (2,363) 4,830 Reconciliation to Group income statement Share of equity accounted unit sales and intra-subsidiary/equity accounted unit sales (2,407) (2,202) (2,313) Impairment charges (1,272) (3,487) (132) Depreciation and amortisation in subsidiaries excluding capitalised depreciation (4,074) (4,272) (3,909) Depreciation and amortisation in equity accounted units (576) (653) (650) Taxation and finance items in equity accounted units (443) (296) (372) Finance items (1,751) (648) (33) Consolidated sales revenue/profit before taxation/net earnings 44,611 43,165 40,522 15,391 11,119 18,167 9,769 8,010 13,638 Capital expenditure (o) for the year ended 31 December Depreciation and Operating assets (p) as at 31 December Employees Rio Tinto interest % 2020 US$m 2019 US$m 2018 US$m 2020 US$m 2019 US$m 2018 US$m 2020 US$m 2019 US$m 2018 US$m 2020 2019 2018 Iron Ore Pilbara (d) 2,919 1,720 1,288 1,819 1,704 1,682 16,253 13,865 14,486 11,522 10,634 10,422 Dampier Salt 68.4 22 21 14 19 19 20 163 152 165 351 347 239 Evaluation projects/other (e) — — — — — — 338 2 2 10 — — Intra-segment (e) — — — — — — (104) — — — — — Total Iron Ore 2,941 1,741 1,302 1,838 1,723 1,702 16,650 14,019 14,653 11,883 10,981 10,661 Aluminium (f) Bauxite 142 387 953 290 286 165 2,593 2,597 2,494 2,853 2,940 2,676 Alumina 228 282 218 138 187 194 2,294 2,009 2,721 2,383 2,269 2,009 Primary Metal 602 658 595 643 682 615 9,361 9,674 9,306 6,282 6,357 6,497 Pacific Aluminium 114 129 115 119 154 149 455 970 1,156 2,469 2,356 2,278 Intra-segment and other (1) — — 1 — (1) 662 780 769 141 127 180 Integrated operations 1,085 1,456 1,881 1,191 1,309 1,122 15,365 16,030 16,446 14,128 14,049 13,640 Other product group items (g) — — (508) — — — — — — — — — Product group operations 1,085 1,456 1,373 1,191 1,309 1,122 15,365 16,030 16,446 14,128 14,049 13,640 Evaluation projects/other — — — — 3 — — — — — — — Total Aluminium 1,085 1,456 1,373 1,191 1,312 1,122 15,365 16,030 16,446 14,128 14,049 13,640 Copper & Diamonds Rio Tinto Kennecott 100.0 618 444 318 472 457 427 2,317 2,012 1,864 2,171 2,066 1,993 Escondida 30.0 178 315 302 428 508 518 2,726 2,871 3,057 1,124 1,068 1,087 Grasberg joint venture (h) — — 171 — — 30 — — — — — 1,615 Oyu Tolgoi and Turquoise Hill (i) 1,038 1,289 1,284 189 208 219 8,111 6,780 6,072 3,450 3,152 2,863 Diamonds (j) 25 38 64 60 144 118 (7) 195 267 885 940 967 Product group operations 1,859 2,086 2,139 1,149 1,317 1,312 13,147 11,858 11,260 7,630 7,226 8,525 Evaluation projects/other 5 1 11 4 3 5 192 152 129 159 150 146 Total Copper & Diamonds 1,864 2,087 2,150 1,153 1,320 1,317 13,339 12,010 11,389 7,789 7,376 8,671 Energy & Minerals Rio Tinto Coal Australia (k) — — 32 — — 34 — — (837) — — 1,005 Iron Ore Company of Canada 58.7 243 255 189 170 172 154 1,009 803 975 2,716 2,617 2,397 Rio Tinto Iron & Titanium (l) 144 249 169 173 193 201 3,390 3,507 3,390 4,151 4,115 4,058 Rio Tinto Borates 100.0 42 43 44 49 60 62 502 525 518 966 924 980 Uranium (m) — 5 8 — 3 4 (71) (363) (406) 364 857 1,324 Product group operations 429 552 442 392 428 455 4,830 4,472 3,640 8,197 8,513 9,764 Simandou iron ore project (n) (2) (1) — — — — 16 20 15 69 74 70 Evaluation projects/other 1 — — — — — 33 37 41 77 53 33 Total Energy & Minerals 428 551 442 392 428 455 4,879 4,529 3,696 8,343 8,640 9,867 Other operations (o) 2 (4) 12 199 177 26 (479) (83) (442) 124 159 187 Inter-segment transactions 129 127 129 Product group total 6,320 5,831 5,279 4,773 4,960 4,622 49,883 46,632 45,871 42,267 41,205 43,026 Net assets of disposal groups held for sale (r) — — 440 Other items 79 64 65 82 77 43 (2,165) (2,449) (2,880) 5,207 4,802 4,432 Less: equity accounted units (255) (456) (500) (576) (653) (650) — — — — — — Total 6,144 5,439 4,844 4,279 4,384 4,015 47,718 44,183 43,431 47,474 46,007 47,458 Add back: Proceeds from disposal of property, plant and equipment 45 49 586 Total capital expenditure per cash flow statement 6,189 5,488 5,430 Less: Net (debt)/cash (664) (3,651) 255 Equity attributable to owners of Rio Tinto 47,054 40,532 43,686 Business units are classified according to the Group’s management structure. The disclosures in this note include certain Alternative performance measures (APMs). For more information on the APMs used by the Group, including definitions and calculations, please refer to pages 329-333. (a) Gross product sales includes the sales revenue of equity accounted units on a proportionately consolidated basis (after adjusting for sales to subsidiaries) in addition to consolidated sales. Consolidated sales revenue includes subsidiary sales to equity accounted units which are not included in gross product sales. (b) Underlying EBITDA of subsidiaries and the Group’s share relating to equity accounted units represents earnings attributable to owners of Rio Tinto before: tax, net finance items, depreciation and amortisation charged to the income statement in the period and excludes the EBITDA impact of the same items that are excluded from underlying earnings as defined in note 2. (c) Represents profit after tax for the period attributable to the owners of the Rio Tinto Group. Business unit earnings are stated before finance items but after the amortisation of discount related to provisions. Earnings attributed to business units do not include amounts that are excluded in arriving at underlying earnings. (d) Pilbara represents the Group’s 100% holding in Hamersley, 50% holding in Hope Downs Joint Venture and 65% holding in Robe River Iron Associates. The Group’s net beneficial interest in Robe River Iron Associates is 53%, as 30% is held through a 60% owned subsidiary and 35% is held through a 100% owned subsidiary. (e) Gross product sales, Underlying EBITDA, Net Earnings and Operating assets within Evaluation projects/other include activities relating to the shipment and blending of Pilbara and Iron Ore Company of Canada (IOC) iron ore inventories held at portside in China and sold to domestic customers. Transactions between the Pilbara and our portside trading business are eliminated through the Iron Ore "intra-segment" line and transactions between IOC and the portside trading business are eliminated through "inter-segment transactions". (f) In order to reflect the evolution of the Aluminium business, the following changes have been implemented: – The consolidation line for Bauxite & Alumina has been removed to reflect the less integrated nature of the business and the evolution of the Bauxite business towards a primarily export oriented operation. As a result of this change, the intra-group segment elimination for Gross product sales, Underlying EBITDA, Net Earnings and Operating assets between bauxite and alumina are now reported on line "Intra-segment and other". The intra-segment eliminations for the year ended 31 December 2020 would have been US$722 million, US$31 million, US$21 million and US$7 million respectively. For the year ended 31 December 2019 the eliminations were US$825 million, US$10 million, US$7 million and US$27 million. For the year ended 31 December 2018 the eliminations were US$861 million, US$7 million, US$5 million and US$20 million. – The Underlying EBITDA and Net Earnings have been restated to include the impact of the legacy alumina contracts (2019: US$218 million and US$171 million, respectively; 2018: US$457 million and US$355 million, respectively) in the Alumina business instead of being included in the Other product group items line, in order to provide a comprehensive view of the performance of the Alumina business. – The Gross product sales, Underlying EBITDA and Net Earnings have been restated to reallocate the margin generated by internal shipping activities to Bauxite (2019: US$31 million, US$76 million and US$57 million, respectively; 2018: US$40 million, US$62 million and US$54 million, respectively) and Alumina businesses (2019: US$63 million, US$157 million and US$117 million, respectively; 2018: US$83 million, US$128 million and US$111 million, respectively), instead of being included in the Evaluation project/other line in order to provide a comprehensive view of the performance of the Bauxite and Alumina businesses. Gross product sales, Underlying EBITDA, Net Earnings and Operating assets of the overall Rio Tinto Aluminium business were not impacted by these changes. (g) In 2018, Aluminium capital expenditure was reported net of US$508 million proceeds received from the sale of surplus land at Kitimat. These proceeds were not included in Aluminium’s free cash flow and the associated gain was excluded from business unit earnings and Underlying EBITDA. (h) Through a joint venture agreement with Freeport-McMoRan Inc. (Freeport), we were entitled to 40% of material mined above an agreed threshold as a consequence of expansions and developments of the Grasberg facilities since 1998 (until 21 December 2018). On 21 December 2018, we sold our entire interest in the Grasberg mine to PT Indonesia Asahan Aluminium (Persero) (Inalum). (i) Our interest in Oyu Tolgoi is held indirectly through our 50.8% investment in Turquoise Hill Resources Ltd (TRQ), where TRQ’s principal asset is its 66% investment in Oyu Tolgoi LLC, which owns the Oyu Tolgoi copper-gold mine. (j) Includes our interests in Argyle (100%) and Diavik (60%). (k) Includes our 82% interest in the Hail Creek coal mine (until 1 August 2018), our 80% interest in the Kestrel underground coal mine (until 1 August 2018) and interests in the Winchester South (until 1 June 2018) and Valeria development projects (until 1 August 2018). On 1 June 2018, we sold our entire 75% interest in the Winchester South coal development project in Queensland, Australia, to Whitehaven Coal Limited for US$200 million. On 1 August 2018, we sold our entire 82% interest in the Hail Creek coal mine and 71.2% interest in the Valeria coal development project in Queensland, Australia, to Glencore for US$1.7 billion . On 1 August 2018, we sold our entire 80% interest in the Kestrel underground coal mine in Queensland, Australia, to a consortium comprising private equity manager EMR Capital (EMR) and PT Adaro Energy Tbk (Adaro), an Indonesian listed coal company, for US$2.25 billion. Rio Tinto Coal Australia’s operating assets of US$(837) million at 31 December 2018 included provisions for onerous contracts in relation to rail infrastructure capacity and capital gains tax payable on the divestments announced in the year, partly offset by financial assets and receivables relating to contingent royalties and disposal proceeds. Following a change in management responsibility in 2019, these amounts are reported within "Other operations" at 31 December 2020 and 31 December 2019, with no restatement of the 31 December 2018 comparative amount. (l) Includes our interests in Rio Tinto Fer et Titane (100%), QIT Madagascar Minerals (QMM, 80%) and Richards Bay Minerals (attributable interest of 74%).

Principal accounting policies (

Principal accounting policies (Policies)	12 Months Ended
	Dec. 31, 2020
Disclosure of initial application of standards or interpretations [abstract]
Accounting convention	(a) Accounting convention The financial information included in the financial statements for the year ended 31 December 2020, and for the related comparative periods, has been prepared under the historical cost convention, as modified by the revaluation of certain derivative contracts and financial assets, the impact of fair value hedge accounting on the hedged item and the accounting for post-employment assets and obligations. The Group’s policy in respect of these items is set out in the notes below. All financial statement values are rounded to the nearest million (US$m) unless otherwise stated. Where applicable, comparatives have been adjusted to measure or present them on the same basis as current period figures.
Basis of consolidation	(b) Basis of consolidation (notes 32-35) All intragroup transactions and balances have been eliminated on consolidation. Where necessary, adjustments are made to the locally reported assets, liabilities, and results of subsidiaries, joint arrangements and associates to bring their accounting policies in line with those used by the Group. Subsidiaries Subsidiaries are entities controlled by either of the companies. Control exists where either of the companies has: power over the entities, that is, existing rights that give it the current ability to direct the relevant activities of the entities (those that significantly affect the companies’ returns); exposure, or rights, to variable returns from its involvement with the entities; and the ability to use its power to affect those returns. Subsidiaries are fully consolidated from the date on which the Group obtains control. They are de-consolidated from the date that control ceases. Joint arrangements A joint arrangement is an arrangement in which two or more parties have joint control. Joint control is the contractually agreed sharing of control such that decisions about the relevant activities of the arrangement (those that significantly affect the companies’ returns) require the unanimous consent of the parties sharing control. The Group has two types of joint arrangements: Joint operations (JO) A JO is a joint arrangement in which the parties that share joint control have rights to the assets, and obligations for the liabilities, relating to the arrangement. This includes situations where the parties benefit from the joint activity through a share of the output, rather than by receiving a share of the results of trading. In relation to its interest in a JO, the Group recognises: its share of assets and liabilities; revenue from the sale of its share of the output and its share of any revenue generated from the sale of the output by the JO; and its share of expenses. All such amounts are measured in accordance with the terms of the arrangement, which is usually in proportion to the Group’s interest in the JO. These amounts are recorded in the Group’s financial statements on the appropriate lines. Joint ventures (JV) A JV is a joint arrangement in which the parties that share joint control have rights to the net assets of the arrangement. JVs are accounted for using the equity accounting method. Other unincorporated arrangements In some cases, the Group participates in unincorporated arrangements and has rights to its share of the assets and obligations for its share of the liabilities of the arrangement rather than a right to a net return, but does not share joint control. In such cases, the Group recognises: its share of assets and liabilities; revenue from the sale of its share of the output and its share of any revenue generated from the sale of the output by the unincorporated arrangement; and its share of expenses. All such amounts are measured in accordance with the terms of the arrangement, which is usually in proportion to the Group’s interest in the arrangement. These amounts are recorded in the Group’s financial statements on the appropriate lines. Associates An associate is an entity that is neither a subsidiary nor a joint arrangement, over which the Group has significant influence. Significant influence is presumed to exist where there is neither control nor joint control and the Group has over 20% of the voting rights, unless it can be clearly demonstrated that this is not the case. Significant influence can arise where the Group holds less than 20% of the voting rights if it has the power to participate in the financial and operating policy decisions affecting the entity. Investments in associates are accounted for using the equity accounting method. The Group uses the term “equity accounted units” (EAUs) to refer to associates and JVs collectively. Under the equity accounting method the investment is recorded initially at cost to the Group, including any goodwill on acquisition. In subsequent periods the carrying amount of the investment is adjusted to reflect the Group’s share of the EAUs’ retained post-acquisition profit or loss and other comprehensive income. Long-term loans to EAUs that in substance form part of the Group’s net investment (quasi equity loans) are financial assets but are included in the line “Investments in equity accounted units” on the face of the balance sheet. When the Group’s share of losses in an EAU equals or exceeds its interest in the EAU, including such long-term loans and any other unsecured receivables, the Group does not recognise further losses, unless it has incurred legal or constructive obligations to continue to make payments on behalf of the EAU. Acquisitions (note 36) Under the “acquisition” method of accounting for business combinations, the purchase consideration is allocated to the identifiable assets acquired and liabilities and contingent liabilities assumed (the identifiable net assets) on the basis of their fair value at the date of acquisition, which is the date on which control is obtained. In determining whether a particular set of activities is a business, an acquired arrangement has to have an input and substantive process which together significantly contribute to the ability to create outputs. 1 Principal accounting policies continued The consideration transferred for the acquisition of a subsidiary comprises the fair values of the assets transferred, the liabilities incurred to the former owners of the acquiree, the fair value of any asset or liability resulting from a contingent consideration arrangement and any equity interests issued by the Group. Costs related to the acquisition of a subsidiary are expensed as incurred. The excess of the consideration transferred, the amount of any non- controlling interest in the acquiree and the acquisition-date fair value of any previous equity interest in the acquiree over the fair value of the identifiable net assets acquired is recorded as goodwill. Any shortfall is immediately recognised in the income statement. Non-controlling interests in the acquiree, that are present ownership interests and entitle their holders to a proportionate share of the entity’s net assets in the event of liquidation, are recognised by the Group in one of two ways with the choice being available on an acquisition-by-acquisition basis. They can be measured at either the non-controlling interest’s proportionate share of the acquiree’s identifiable net assets or at fair value. In some cases, non-controlling interests may be treated as equity options and valued on that basis. Goodwill (see note 1(e)) and amounts attributable to non-controlling interests will differ depending on the basis used. Where the Group previously held a non-controlling interest in the acquiree, this is remeasured to fair value at the date control is obtained with any gain or loss recognised in the income statement. The cash cost of the share purchase that gives rise to control is included within “investing activities” in the cash flow statement. Where the Group increases its ownership interest in a subsidiary, the difference between the purchase price and the carrying value of the share of net assets acquired is recorded in equity. The cash cost of such purchases is included within “financing activities” in the cash flow statement. Provisional fair values allocated at a reporting date are finalised within 12 months of the acquisition date. The results of businesses acquired during the year are included in the consolidated financial statements from the date on which control, joint control or significant influence is obtained. Disposals (note 36) Individual non-current assets or “disposal groups” (that is, groups of assets and liabilities) to be disposed of by sale or otherwise in a single transaction are classified as “held for sale” if the following criteria are met at the period end: – The carrying amount will be recovered principally through a sale transaction rather than through continuing use; and – The disposal group is available for immediate sale in its present condition subject only to terms that are usual and customary for such sales; and – The sale is highly probable. Disposal groups held for sale are carried at the lower of their carrying amount and fair value less costs to sell. The comparative balance sheet is not restated. Disposal groups acquired with a view to resale are held at the fair value determined at the acquisition date. For these assets acquired for resale no profits or losses are recognised between the acquisition date and the disposal date, unless there is a subsequent impairment. On classification as held for sale, the assets are no longer depreciated and, if applicable, equity accounting ceases.
Sales revenue	(c) Sales revenue Recognition and measurement The Group recognises sales revenue related to the transfer of promised goods or services when control of the goods or services passes to the customer. The amount of revenue recognised reflects the consideration to which the Group is or expects to be entitled in exchange for those goods or services. Sales revenue is recognised on individual sales when control transfers to the customer. In most instances, control passes and sales revenue is recognised when the product is delivered to the vessel or vehicle on which it will be transported once loaded, the destination port or the customer’s premises. There may be circumstances when judgment is required based on the five indicators of control below. – The customer has the significant risks and rewards of ownership and has the ability to direct the use of, and obtain substantially all of the remaining benefits from, the good or service. – The customer has a present obligation to pay in accordance with the terms of the sales contract. For shipments under the Incoterms Cost, Insurance and Freight (CIF)/Carriage Paid to (CPT)/Cost and Freight (CFR) this is generally when the ship is loaded, at which time the obligation for payment is for both product and freight. – The customer has accepted the asset. Sales revenue may be subject to adjustment if the product specification does not conform to the terms specified in the sales contract but this does not impact the passing of control. Assay and specification adjustments have been immaterial historically. – The customer has legal title to the asset. The Group usually retains legal title until payment is received for credit risk purposes only. – The customer has physical possession of the asset. This indicator may be less important as the customer may obtain control of an asset prior to obtaining physical possession, which may be the case for goods in transit. The Group sells a significant proportion of its products on CFR or CIF Incoterms. This means that the Group is responsible (acts as principal) for providing shipping services and, in some instances, insurance after the date at which control of goods passes to the customer at the loading port. The Group therefore has separate performance obligations for freight and insurance services that are provided solely to facilitate sale of the commodities it produces. Other Incoterms commonly used by the Group are Free on Board (FOB), where the Group has no responsibility for freight or insurance once control of the goods has passed at the loading port, and Delivered at Place (DAP), where control of the goods passes when the product is delivered to the agreed destination. For these Incoterms there is only one performance obligation, being for provision of product at the point where control passes. The Group’s products are sold to customers under contracts which vary in tenure and pricing mechanisms, including some volumes sold in the spot market. Pricing for iron ore is on a range of terms, the majority being either monthly or quarterly average pricing mechanisms, with a smaller proportion of iron ore volumes being sold on the spot market. Within each sales contract, each unit of product shipped is a separate performance obligation. Revenue is generally recognised at the contracted price as this reflects the stand-alone selling price. Sales revenue excludes any applicable sales taxes. Mining royalties payable are presented as an operating cost or, where they are in substance a profit-based tax, within taxation. Sales of copper concentrate are stated net of the treatment and refining charges which will be required to convert it to an end product. Certain of the Group’s products may be provisionally priced at the date revenue is recognised; however, substantially all iron ore and aluminium sales are reflected at final prices in the results for the period. The final selling price for all provisionally priced products is based on the price for the quotational period stipulated in the contract. Final prices for copper concentrate are normally determined between 30-120 days after delivery to the customer. The change in value of the provisionally priced receivable is based on relevant forward market prices and is included in sales revenue. Rio Tinto has a number of long-term contracts to supply product to customers in future periods. Generally, revenues are recognised on an as invoiced basis; hence, the right to consideration from a customer corresponds directly with the entity’s performance completed to date. A number of the Group’s businesses provide volume discounts in certain circumstances. The impact of constraining such variable consideration under IFRS 15 was immaterial at both 31 December 2020 and 31 December 2019. The Group applies the practical expedient in paragraph 121 of IFRS 15 and does not disclose information on the transaction price allocated to performance obligations that are unsatisfied. Presentation and disclosures Consolidated sales revenue as reported in the income statement comprises sales to third parties. Certain of the Group’s products may be provisionally priced at the date revenue is recognised. Sales revenue includes revenue from contracts with customers, which is accounted for under IFRS 15 “Revenue from Contracts with Customers” and subsequent movements in provisionally priced receivables which are accounted for under IFRS 9 “Financial Instruments”. A breakdown of sales revenue between these two amounts is disclosed in the product analysis in note 3 and further detail on provisional pricing in note 3. Sales revenue includes revenue from movements in provisionally priced receivables, consistent with the treatment in prior periods. The Group considers that the impact of economic factors on its sales revenue, particularly pricing and volumes, is best understood by reference to the disclosure of sales revenue by product group and sales destination in note 3. The analysis of provisional pricing adjustments by commodity in the product analysis in note 3 shows which products are subject to price volatility post the transfer of control. With the exception of Oyu Tolgoi, which sells copper concentrate to China, this price uncertainty is largely resolved at the period end. Typically, the Group has a right to payment before or at the point that control of the goods passes including a right, where applicable, to payment for provisionally priced products and unperformed freight and insurance services. Cash received before control passes is recognised as a contract liability. The amount of consideration does not contain a significant financing component as payment terms are less than one year. Revenues from the sale of significant by-products, such as gold, are included in sales revenue. Sundry revenue (eg sales of surplus power) incidental to the main revenue-generating activities of the operations is treated as a credit to operating costs. The Group does not disclose sales revenue from freight and insurance services separately as it does not consider that this is necessary in order to understand the impact of economic factors on the Group; the Group’s Chief Executive, the chief operating decision maker, as defined under IFRS 8, “Operating Segments”, does not review information specifically relating to these sources of revenue in order to evaluate the performance of business segments and Group information on these sources of revenue is not provided externally.
Currency translation	(d) Currency translation The functional currency for each entity in the Group, and for joint arrangements and associates, is the currency of the primary economic environment in which that entity operates. For many of these entities, this is the currency of the country in which they are located. Transactions denominated in other currencies are converted to the functional currency at the exchange rate ruling at the date of the transaction. Monetary assets and liabilities denominated in foreign currencies are retranslated at period-end exchange rates. The Group’s financial statements are presented in US dollars, as that presentation currency most reliably reflects the global business performance of the Group as a whole. On consolidation, income statement items for each entity are translated from the functional currency into US dollars at average rates of exchange, except for material one-off transactions, which are translated at the rate prevailing on the transaction date. Balance sheet items are translated into US dollars at period-end exchange rates. Exchange differences arising on the translation of the net assets of entities with functional currencies other than the US dollar are recognised directly in the currency translation reserve. These translation differences are shown in the statement of comprehensive income, with the exception of translation adjustments relating to Rio Tinto Limited’s share capital which are shown in the statement of changes in equity. Where an intragroup balance is, in substance, part of the Group’s net investment in an entity, exchange gains and losses on that balance are taken to the currency translation reserve.
Goodwill and intangible assets (excluding exploration and evaluation expenditure)	(e) Goodwill and intangible assets (excluding exploration and evaluation expenditure) (notes 12 and 13) Goodwill is not amortised; it is tested annually for impairment or more frequently if events or changes in circumstances indicate a potential impairment. Investments in EAUs, including any goodwill, are tested for impairment as a single asset when a trigger for impairment has been identified. The Group’s impairment policy is explained in note 1(i). 1 Principal accounting policies continued Purchased intangible assets are initially recorded at cost. Finite-life intangible assets are amortised over their useful economic lives on a straight line or units of production basis, as appropriate. Intangible assets that are deemed to have indefinite lives and intangible assets that are not yet ready for use are not amortised; they are reviewed annually for impairment or more frequently if events or changes in circumstances indicate a potential impairment in accordance with accounting policy note 1(i).
Exploration and evaluation	(f) Exploration and evaluation (note 13) Exploration and evaluation expenditure comprises costs that are directly attributable to: – Researching and analysing existing exploration data; – Conducting geological studies, exploratory drilling and sampling; – Examining and testing extraction and treatment methods; and/or – Compiling various studies (order of magnitude, pre-feasibility and feasibility). Exploration expenditure relates to the initial search for deposits with economic potential. Expenditure on exploration activity undertaken by the Group is not capitalised. Evaluation expenditure relates to a detailed assessment of deposits or other projects (including smelter and refinery projects) that have been identified as having economic potential. Capitalisation of evaluation expenditure commences when there is a high degree of confidence that the Group will determine that a project is commercially viable, that is the project will provide a satisfactory return relative to its perceived risks, and therefore it is considered probable that future economic benefits will flow to the Group. The Group’s view is that a high degree of confidence is greater than “more likely than not” (that is, greater than 50% certainty) and less than “virtually certain” (that is, less than 90% certainty). Assessing whether there is a high degree of confidence that the Group will ultimately determine that an evaluation project is commercially viable requires judgment and consideration of all relevant factors such as the nature and objective of the project; the project’s current stage; project timeline; current estimates of the project’s net present value, including sensitivity analyses for the key assumptions; and the main risks of the project. Development expenditure incurred prior to the decision to proceed is subject to the same criteria for capitalisation, being a high degree of confidence that the Group will ultimately determine that a project is commercially viable. In some cases, undeveloped projects are regarded as successors to orebodies, smelters or refineries currently in production. Where this is the case, it is intended that these will be developed and go into production when the current source of ore is exhausted or when existing smelters or refineries are closed. Ore reserves may be declared for an undeveloped mining project before its commercial viability has been fully determined. Evaluation costs may continue to be capitalised during the period between declaration of ore reserves and approval to mine as further work is undertaken in order to refine the development case to maximise the project’s returns. In accordance with IFRS 6 “Exploration for and Evaluation of Mineral Resources”, the criteria for the capitalisation of evaluation costs are applied consistently from period to period. In the case of undeveloped mining projects which have arisen through acquisition, the allocation of the purchase price consideration may result in undeveloped properties being recognised at an earlier stage of project evaluation compared with projects arising from the Group’s exploration and evaluation programme. Subsequent expenditure on acquired undeveloped projects is only capitalised if it meets the high degree of confidence threshold discussed above. The carrying values of capitalised evaluation expenditure for undeveloped mining projects (projects for which the decision to mine has not yet been approved at the appropriate authorisation level within the Group) are reviewed at each reporting date for indicators of impairment in accordance with IFRS 6, and when indicators are identified are tested in accordance with IAS 36. Evaluation expenditure for non-mining projects is reviewed and tested under IAS 36.
Property, plant and equipment	(g) Property, plant and equipment (note 14) Once an undeveloped mining project has been determined as commercially viable and approval to mine has been given, expenditure other than that on land, buildings, plant, equipment and capital work in progress is capitalised under “Mining properties and leases” together with any amount transferred from “Exploration and evaluation”. Costs which are necessarily incurred whilst commissioning new assets, in the period before they are capable of operating in the manner intended by management, are capitalised. Development costs incurred after the commencement of production are capitalised to the extent they are expected to give rise to a future economic benefit. Interest on borrowings related to construction or development projects is capitalised, at the rate payable on project-specific debt if applicable or at the Group or subsidiary’s cost of borrowing if not, until the point when substantially all the activities that are necessary to make the asset ready for its intended use are complete. It may be appropriate to use a subsidiary’s cost of borrowing when the debt was negotiated based on the financing requirements of that subsidiary. Property, plant and equipment is stated at cost, as defined in IAS 16, less accumulated depreciation and accumulated impairment losses. The cost of property, plant and equipment includes, where applicable, the estimated close-down and restoration costs associated with the asset.
Deferred stripping	(h) Deferred stripping (note 14) In open pit mining operations, overburden and other waste materials must be removed to access ore from which minerals can be extracted economically. The process of removing overburden and waste materials is referred to as stripping. During the development of a mine (or, in some instances, pit; see below), before production commences, stripping costs related to a component of an orebody are capitalised as part of the cost of construction of the mine (or pit) and are subsequently amortised over the life of the mine (or pit) on a units of production basis. Where a mine operates several open pits that are regarded as separate operations for the purpose of mine planning, initial stripping costs are accounted for separately by reference to the ore from each separate pit. If, however, the pits are highly integrated for the purpose of mine planning, the second and subsequent pits are regarded as extensions of the first pit in accounting for stripping costs. In such cases, the initial stripping (ie overburden and other waste removal) of the second and subsequent pits is considered to be production phase stripping (see below). The Group’s judgment as to whether multiple pit mines are considered separate or integrated operations depends on each mine’s specific circumstances. The following factors would point towards the initial stripping costs for the individual pits being accounted for separately: – If mining of the second and subsequent pits is conducted consecutively following that of the first pit, rather than concurrently; – If separate investment decisions are made to develop each pit, rather than a single investment decision being made at the outset; – If the pits are operated as separate units in terms of mine planning and the sequencing of overburden removal and ore mining, rather than as an integrated unit; – If expenditures for additional infrastructure to support the second and subsequent pits are relatively large; and – If the pits extract ore from separate and distinct orebodies, rather than from a single orebody. If the designs of the second and subsequent pits are significantly influenced by opportunities to optimise output from several pits combined, including the co-treatment or blending of the output from the pits, then this would point to treatment as an integrated operation for the purposes of accounting for initial stripping costs. The relative importance of each of the above factors is considered in each case. In order for production phase stripping costs to qualify for capitalisation as a stripping activity asset, three criteria must be met: – It must be probable that there will be an economic benefit in a future accounting period because the stripping activity has improved access to the orebody; – It must be possible to identify the “component” of the orebody for which access has been improved; and – It must be possible to reliably measure the costs that relate to the stripping activity. A “component” is a specific section of the orebody that is made more accessible by the stripping activity. It will typically be a subset of the larger orebody that is distinguished by a separate useful economic life (for example, a pushback). Production phase stripping can give rise to two benefits: the extraction of ore in the current period and improved access to ore which will be extracted in future periods. When the cost of stripping which has a future benefit is not distinguishable from the cost of producing current inventories, the stripping cost is allocated to each of these activities based on a relevant production measure using a life-of-component strip ratio. The ratio divides the tonnage of waste mined for the component for the period either by the quantity of ore mined for the component or by the quantity of minerals contained in the ore mined for the component. In some operations, the quantity of ore is a more appropriate basis for allocating costs, particularly where there are significant by-products. Stripping costs for the component are deferred to the extent that the current period ratio exceeds the life of component ratio. The stripping activity asset is depreciated on a “units of production” basis based on expected production of either ore or minerals contained in the ore over the life of the component unless another method is more appropriate. The life-of-component ratios are based on the ore reserves of the mine (and for some mines, other mineral resources) and the annual mine plan; they are a function of the mine design and, therefore, changes to that design will generally result in changes to the ratios. Changes in other technical or economic parameters that impact the ore reserves (and for some mines, other mineral resources) may also have an impact on the life-of-component ratios even if they do not affect the mine design. Changes to the ratios are accounted for prospectively. It may be the case that subsequent phases of stripping will access additional ore and that these subsequent phases are only possible after the first phase has taken place. Where applicable, the Group considers this on a mine-by-mine basis. Generally, the only ore attributed to the stripping activity asset for the purposes of calculating a life-of-component ratio, and for the purposes of amortisation, is the ore to be extracted from the originally identified component.
Depreciation of non-current assets	Depreciation of non-current assets Property, plant and equipment is depreciated over its useful life, or over the remaining life of the mine or smelter or refinery if that is shorter and there is no reasonable alternative use for the asset by the Group. The useful lives of the major assets of a cash-generating unit are often dependent on the life of the orebody to which they relate. Where this is the case, the lives of mining properties, and their associated refineries, concentrators and other long-lived processing equipment are generally limited to the expected life of the orebody. The life of the orebody, in turn, is estimated on the basis of the life-of-mine plan. Where the major assets of a cash-generating unit are not dependent on the life of a related orebody, management applies judgment in estimating the remaining service potential of long-lived assets. Factors affecting the remaining service potential of smelters include, for example, smelter technology and electricity purchase contracts when power is not sourced from the companies, or in some cases from local governments permitting electricity generation from hydro-power stations. The useful lives and residual values for material assets and categories of assets are reviewed annually and changes are reflected prospectively. Depreciation commences when an asset is available for use. The major categories of property, plant and equipment are depreciated on a units of production and/or straight line basis as follows: Units of production basis For mining properties and leases and certain mining equipment, consumption of the economic benefits of the asset is linked to production. Except as noted below, these assets are depreciated on the units of production basis. 1 Principal accounting policies continued In applying the units of production method, depreciation is normally calculated based on production in the period as a percentage of total expected production in current and future periods based on ore reserves and, for some mines, other mineral resources. Other mineral resources may be included in the calculations of total expected production in limited circumstances where there are very large areas of contiguous mineralisation, for which the economic viability is not sensitive to likely variations in grade, as may be the case for certain iron ore, bauxite and industrial mineral deposits, and where there is a high degree of confidence that the other mineral resources can be extracted economically. This would be the case when the other mineral resources do not yet have the status of ore reserves merely because the necessary detailed evaluation work has not yet been performed and the responsible technical personnel agree that inclusion of a proportion of measured and indicated resources in the calculation of total expected production is appropriate based on historical reserve conversion rates. The required level of confidence is unlikely to exist for minerals that are typically found in low-grade ore (as compared with the above), such as copper or gold. In these cases, specific areas of mineralisation have to be evaluated in detail before their economic status can be predicted with confidence. Where measured and indicated resources are used in the calculation of depreciation for infrastructure, primarily rail and port, which will benefit current and future mines, then the measured and indicated resources may relate to mines which are currently in production or to mines where there is a high degree of confidence that they will be brought into production in the future. The quantum of mineral resources is determined taking into account future capital costs as required by the JORC code. The depreciation calculation, however, applies to current mines only and does not take into account future development costs for mines which are not yet in production. Measured and indicated resources are currently incorporated into depreciation calculations in the Group’s Australian iron ore business. Straight line basis Assets within operations for which production is not expected to fluctuate significantly from one year to another or which have a physical life shorter than the related mine are depreciated on a straight line basis.
Impairment charges/reversals of non-current assets	Impairment charges/reversals of non-current assets Impairment charges and reversals are assessed at the level of cash- generating units which, in accordance with IAS 36 “Impairment of Assets”, are identified as the smallest identifiable asset or group of assets that generate cash inflows which are largely independent of the cash inflows from other assets. Separate cash-generating units are identified where an active market exists for intermediate products, even if the majority of those products are further processed internally. Impairment of financial assets is evaluated in accordance with IFRS 9. In some cases, individual business units consist of several operations with independent cash-generating streams which constitute separate cash- generating units. Goodwill acquired through business combinations is allocated to the cash-generating unit or groups of cash-generating units that are expected to benefit from the related business combination, and tested for impairment at the lowest level within the Group at which goodwill is monitored for internal management purposes. All goodwill, intangible assets that have an indefinite life and intangible assets that are not ready for use are tested annually for impairment as at 30 September, regardless of whether there has been an impairment trigger, or more frequently if events or changes in circumstances indicate a potential impairment. Property, plant and equipment and intangible assets with finite lives are reviewed for impairment if there is an indication that the carrying amount may not be recoverable. Right of use assets recognised under IFRS 16 "Leases" are included in the review. The Group conducts an internal review of the asset values annually as at 30 September which is used as a source of information to assess for indications of impairment or reversal of previously recognised impairment losses. External factors, such as changes in forecasted commodity prices, costs and other market factors as well as internal factors such as cancellation of a project or reduced project scope, are also monitored to assess for indications of impairment or reversal of previously recognised impairment losses. If any such indication exists then an impairment review is undertaken; the recoverable amount is assessed by reference to the higher of value in use (being the net present value of expected future cash flows of the relevant cash-generating unit in its current condition) and fair value less costs of disposal (FVLCD). When the recoverable amount of the cash-generating unit is measured by reference to FVLCD, this amount is further classified in accordance with the fair value hierarchy for observable market data that is consistent with the unit of account for the cash-generating unit being tested. The Group considers that the best evidence of FVLCD is the value obtained from an active market or binding sale agreement and, in this case, the recoverable amount is classified in the fair value hierarchy as level 1. When FVLCD is based on quoted prices for equity instruments but adjusted to reflect factors such as a lack of liquidity in the market, the recoverable amount is classified as level 2 in the fair value hierarchy. No cash-generating units are currently assessed for impairment by reference to a recoverable amount based on FVLCD classified as level 1 or level 2. Where unobservable inputs are material to the measurement of the recoverable amount, FVLCD is based on the best information available to reflect the amount the Group could receive for the cash-generating unit in an orderly transaction between market participants at the measurement date. This is often estimated using discounted cash flow techniques and is classified as level 3 in the fair value hierarchy. Where the recoverable amount is assessed using FVLCD based on discounted cash flow techniques, the resulting estimates are based on detailed life-of-mine and/or long-term production plans. These may include anticipated expansions which are at the evaluation stage of study. The cash flow forecasts for FVLCD purposes are based on management’s best estimates of expected future revenues and costs, including the future cash costs of production, capital expenditure, and closure, restoration and environmental costs. For the purposes of determining FVLCD from a market participant’s perspective, the cash flows incorporate management’s price and cost assumptions in the short and medium term. In the longer term, operating margins are assumed to remain constant where appropriate, as it is considered unlikely that a market participant would prepare detailed forecasts over a longer term. The cash flow forecasts may include net cash flows expected to be realised from the extraction, processing and sale of material that does not currently qualify for inclusion in ore reserves. Such non-reserve material is only included when there is a high degree of confidence in its economic extraction. This expectation is usually based on preliminary drilling and sampling of areas of mineralisation that are contiguous with existing ore reserves. Typically, the additional evaluation required to achieve reserves status for such material has not yet been done because this would involve incurring evaluation costs earlier than is required for the efficient planning and operation of the mine. As noted above, cost levels incorporated in the cash flow forecasts for FVLCD purposes are based on the current life-of-mine plan or long-term production plan for the cash-generating unit. This differs from value in use which requires future cash flows to be estimated for the asset in its current condition and therefore does not include future cash flows associated with improving or enhancing an asset’s performance. Anticipated enhancements to assets may be included in FVLCD calculations and, therefore, generally result in a higher value. Where the recoverable amount of a cash-generating unit is dependent on the life of its associated orebody, expected future cash flows reflect the current life of mine and/or long-term production plans, which are based on detailed research, analysis and iterative modelling to optimise the level of return from investment, output and sequence of extraction. The mine plan takes account of all relevant characteristics of the orebody, including waste-to-ore ratios, ore grades, haul distances, chemical and metallurgical properties of the ore impacting process recoveries and capacities of processing equipment that can be used. The life-of-mine plan and/or long-term production plans are, therefore, the basis for forecasting production output and production costs in each future year. Forecast cash flows for ore reserve estimation for JORC purposes are generally based on Rio Tinto’s commodity price forecasts, which assume short-term market prices will revert to the Group’s assessment of the long-term price, generally over a period of three to five years. For most commodities, these forecast commodity prices are derived from a combination of analyses of the marginal costs of the producers and of the incentive price of these commodities. These assessments often differ from current price levels and are updated periodically. The Group does not believe that published medium- and long-term forward prices necessarily provide a good indication of future levels because they tend to be strongly influenced by spot prices. The price forecasts used for ore reserve estimation are generally consistent with those used for impairment testing unless management deems that in certain economic environments, a market participant would not assume Rio Tinto’s view on prices, in which case in preparing FVLCD impairment calculations management estimates the assumptions that a market participant would be expected to use. Forecast future cash flows of a cash-generating unit take into account the sales prices under existing sales contracts. The discount rates applied to the future cash flow forecasts represent an estimate of the rate the market would apply having regard to the time value of money and the risks specific to the asset for which the future cash flow estimates have not been adjusted. The Group’s weighted average cost of capital is generally used as a starting point for determining the discount rates, with appropriate adjustments for the risk profile of the countries in which the individual cash-generating units operate. For final feasibility studies and ore reserve estimation, internal hurdle rates, which are generally higher than the Group’s weighted average cost of capital, are used. For developments funded with project finance, the debt component of the weighted average cost of capital may be calculated by reference to the specific interest rate of the project finance and anticipated leverage of the project. For operations with a functional currency other than the US dollar, the impairment review is undertaken in the relevant functional currency. In estimating FVLCD, internal forecasts of exchange rates take into account spot exchange rates, historical data and external forecasts, and are kept constant in real terms after five years. The great majority of the Group’s sales are based on prices denominated in US dollars. To the extent that the currencies of countries in which the Group produces commodities strengthen against the US dollar without an increase in commodity prices, cash flows and, therefore, net present values are reduced. Management considers that over the long term, there is a tendency for movements in commodity prices to compensate to some extent for movements in the value of the US dollar, particularly against the Australian dollar and Canadian dollar, and vice versa. However, such compensating changes are not synchronised and do not fully offset each other. In estimating value in use, the present value of future cash flows in foreign currencies is translated at the spot exchange rate on the testing date. Non-current assets (excluding goodwill) that have suffered impairment are reviewed using the same basis for valuation as explained above whenever events or changes in circumstances indicate that the impairment loss may no longer exist, or may have decreased. If appropriate, an impairment reversal will be recognised. The carrying amount of the cash-generating unit after reversal must be the lower of (a) the recoverable amount, as calculated above, and (b) the carrying amount that would have been determined (net of amortisation or depreciation) had no impairment loss been recognised for the cash-generating unit in prior periods.
Determination of ore reserve and mineral resource estimates	(j) Determination of ore reserve and mineral resource estimates The Group estimates its ore reserves and mineral resources based on information compiled by Competent Persons as defined in accordance with the JORC code. Ore reserves and, for certain mines, other mineral resources, determined in this way are used in the calculation of depreciation, amortisation and impairment charges and for forecasting the timing of the payment of close-down and restoration costs and the recovery of deferred tax assets. The depreciation and impairment policy above notes instances in which mineral resources are taken into account for accounting purposes. In addition, value may be attributed to mineral resources in purchase price allocations undertaken for the purposes of business combination accounting. For the purposes of disclosure only with this combined Annual report on Form 20-F, estimates of ore reserves have been computed in accordance with the SEC’s Industry Guide 7, rather than in accordance with the JORC code, and are shown on pages 341 to 347. This information is unaudited. Ore reserves presented in accordance with SEC Industry Guide 7 do not exceed the quantities that, it is estimated, could be extracted economically if future prices were to be in line with the average of historical prices for the three years to 30 June 2020, or contracted prices where applicable. For this purpose, contracted prices are applied only to future sales volumes for which the price is predetermined by an existing contract; and the average of historical prices is applied to expected sales volumes in excess of such amounts. Moreover, reported ore reserve estimates have not been increased above the levels expected to be economic based on Rio Tinto’s own long-term price assumptions. Therefore, a reduction in commodity prices from the three-year average historical price levels would not necessarily give rise to a reduction in reported ore reserves.
Leases	(k) Leases (notes 14, 21, 22) IFRS 16 “Leases” applies to the recognition, measurement, presentation and disclosure of leases. Certain leases are exempt from the standard, including leases to explore for or use minerals, oil, natural gas and similar non-regenerative resources. The Group does not apply IFRS 16 to arrangements which fall within the scope of IAS 38 “Intangible Assets”. A significant proportion by value of the Group’s lease arrangements relate to dry bulk vessels and offices. Other leases include land and non-mining rights, warehouses, ports, equipment and vehicles. The majority of lease terms are negotiated through the Group’s procurement function, although agreements contain a wide range of different terms and conditions. The Group recognises all lease liabilities and corresponding right of use assets, with the exception of short-term (12 months or fewer) and low value leases, on the balance sheet. Lease liabilities are recorded at the present value of: fixed payments; variable lease payments that depend on an index or rate; amounts payable under residual value guarantees; and extension options expected to be exercised. Where a lease contains an extension option which the Group can exercise without negotiation, lease payments for the extension period are included in the liability if the Group is reasonably certain that it will exercise the option. Variable lease payments not dependent on an index or rate are excluded from the calculation of lease liabilities. Payments are discounted at the incremental borrowing rate of the lessee, unless the interest rate implicit in the lease can be readily determined. For lease agreements relating to vessels, ports and properties, non-lease components are excluded from the projection of future lease payments and recorded separately within operating costs on a straight line basis. The lease liability is measured at amortised cost using the effective interest method. The right of use asset arising from a lease arrangement at initial recognition reflects the lease liability, initial direct costs, lease payments made before the commencement date of the lease, and capitalised provision for dismantling and restoration, less any lease incentives. 1 Principal accounting policies continued
Close-down, restoration and environmental obligations	(l) Close-down, restoration and environmental obligations (note 25) The Group has provisions for close-down and restoration costs which include the dismantling and demolition of infrastructure, the removal of residual materials and the remediation of disturbed areas for mines and certain refineries and smelters. These provisions are based on all regulatory requirements and any other commitments made to stakeholders. Closure provisions are not made for those operations that have no known restrictions on their lives as the closure dates cannot be reliably estimated. This applies primarily to certain Canadian smelters which have indefinite- lived water rights from local governments permitting electricity generation from hydro-power stations. Close-down and restoration costs are a normal consequence of mining or production, and the majority of close-down and restoration expenditure is incurred in the years following closure of the mine, refinery or smelter. Although the ultimate cost to be incurred is uncertain, the Group’s businesses estimate their costs using current restoration standards and techniques. Close-down and restoration costs are provided for in the accounting period when the obligation arising from the related disturbance occurs, based on the net present value of the estimated future costs of restoration to be incurred during the life of the operation and post closure. Where appropriate, the provision is estimated using probability weighting of the different remediation and closure scenarios. The obligation may occur during development or during the production phase of a facility. Provisions for close-down and restoration costs do not include any additional obligations which are expected to arise from future disturbance. The costs are estimated on the basis of a closure plan, and are reviewed at each reporting period during the life of the operation to reflect known developments. The estimates are also subject to formal review, with appropriate external support, at regular intervals. The initial close-down and restoration provision is capitalised within “Property, plant and equipment”. Subsequent movements in the close- down and restoration provisions for ongoing operations, including those resulting from new disturbance related to expansions or other activities qualifying for capitalisation, updated cost estimates, changes to the estimated lives of operations, changes to the timing of closure activities and revisions to discount rates are also capitalised within “Property, plant and equipment”. These costs are then depreciated over the lives of the assets to which they relate. Changes in closure provisions relating to closed operations are charged/credited to “Net operating costs” in the income statement. Where rehabilitation is conducted systematically over the life of the operation, rather than at the time of closure, provision is made for the estimated outstanding continuous rehabilitation work at each balance sheet date and the cost is charged to the income statement. In the context of current market volatility and uncertainty, the Group has taken a long-term view of interest rates into account in determining the appropriate discount rate for discounting of future costs for close-down, restoration and environmental obligations. The amortisation or “unwinding” of the discount applied in establishing the provisions is charged to the income statement in each accounting period. The amortisation of the discount is shown within “Finance items” in the income statement. In some cases, Group companies make a contribution to trust funds in order to meet or reimburse future environmental and decommissioning costs. Amounts due for reimbursement from trust funds are not offset against the corresponding closure provision unless payments into the fund have the effect of passing the closure obligation to the trust. Environmental costs result from environmental damage that was not a necessary consequence of operations, and may include remediation, compensation and penalties. Provision is made for the estimated present value of such costs at the balance sheet date. These costs are charged to “Net operating costs”, except for the unwinding of the discount which is shown within “Finance items”.
Inventories	(m) Inventories (note 16) Inventories are valued at the lower of cost and net realisable value, primarily on a weighted average cost basis. Average costs are calculated by reference to the cost levels experienced in the relevant month together with those in opening inventory. The cost of raw materials and consumable stores is the purchase price. The cost of partly-processed and saleable products is generally the cost of production, including: – Labour costs, materials and contractor expenses which are directly attributable to the extraction and processing of ore or the production of alumina and aluminium; – The depreciation of mining properties and leases and of property, plant and equipment used in the extraction and processing of ore or the production of alumina and aluminium, copper and other refined products; and – Production overheads.
Taxation	(n) Taxation (note 9 and note 17) Current tax is the tax expected to be payable on the taxable income for the year calculated using rates that have been enacted or substantively enacted at the balance sheet date. It includes adjustments for tax expected to be payable or recoverable in respect of previous periods. Where the amount of tax payable or recoverable is uncertain, Rio Tinto establishes provisions based on either: the Group’s judgment of the most likely amount of the liability or recovery; or, when there is a wide range of possible outcomes, a probability weighted average approach.
Post-employment benefits	(o) Post-employment benefits (note 42) The Group operates a number of defined benefit plans which provide lump sums, pensions, medical benefits and life insurance to retirees. In accordance with IAS 19, for post-employment defined benefit plans, the difference between the fair value of any plan assets and the present value of the plan obligations is recognised as an asset or liability in the balance sheet. Where appropriate, the recognition of assets may be restricted to the present value of any amounts the Group expects to recover by way of refunds from the plan or reductions in future contributions. In determining the extent to which a refund will be available the Group considers whether any third party, such as a trustee or pension committee, has the power to enhance benefits or to wind up a pension plan without the Group’s consent. The most significant assumptions used in accounting for pension plans are the discount rate, the inflation rate and mortality rates. The discount rate is used to determine the net present value of the obligations, the interest cost on the obligations and the interest income on plan assets. The discount rate used is the yield on high-quality corporate bonds with maturities and terms that match those of the post-employment obligations as closely as possible. Where there is no developed corporate bond market in a currency, the rate on government bonds is used. The inflation rate is used to project increases in future benefit payments for those plans that have benefits linked to inflation. The mortality rates are used to project the period over which benefits will be paid, which is then discounted to arrive at the net present value of the obligations. The current service cost, any past service cost and the effect of any curtailment or settlements are recognised in the income statement. The interest cost less interest income on assets held in the plans is also charged to the income statement. All amounts charged to the income statement in respect of these plans are included within “Net operating costs” or in “Share of profit after tax of equity accounted units”, as appropriate.
Cash and cash equivalents	(p) Cash and cash equivalents (note 20) For the purpose of the balance sheet, cash and cash equivalents comprise: cash on hand, deposits held with banks, and short-term, highly liquid investments (mainly money market funds) that are readily convertible into known amounts of cash and which are subject to insignificant risk of changes in value. Bank overdrafts are shown as current liabilities in the balance sheet. Further detail on cash and cash equivalents, including restricted cash, is shown in note 20.
Financial instruments	(q) Financial instruments (note 29) (i) Financial assets Classification and measurement The Group classifies its financial assets into the following categories: those to be measured subsequently at fair value (either through other comprehensive income (FVOCI) or through the income statement (FVPL)) and those to be held at amortised cost. Classification depends on the business model for managing the financial assets and the contractual terms of the cash flows. Management determines the classification of financial assets at initial recognition. The Group’s policy with regard to financial risk management is set out in note 29. Generally, the Group does not acquire financial assets for the purpose of selling in the short term. The Group’s business model is primarily that of “hold to collect” (where assets are held in order to collect contractual cash flows). When the Group enters into derivative contracts, these transactions are designed to reduce exposures relating to assets and liabilities, firm commitments or anticipated transactions. (a) Financial assets held at amortised cost This classification applies to debt instruments which are held under a hold to collect business model and which have cash flows that meet the “solely payments of principal and interest” (SPPI) criteria. At initial recognition, trade receivables that do not have a significant financing component are recognised at their transaction price. Other financial assets are initially recognised at fair value plus related transaction costs; they are subsequently measured at amortised cost using the effective interest method. Any gain or loss on de-recognition or modification of a financial asset held at amortised cost is recognised in the income statement. (b) Financial assets held at fair value through other comprehensive income (FVOCI) This classification applies to the following financial assets: – Debt instruments that are held under a business model where they are held for the collection of contractual cash flows and also for sale (“collect and sell”) and which have cash flows that meet the SPPI criteria. An example would be where trade receivable invoices for certain customers were factored from time to time. All movements in the fair value of these financial assets are taken through other comprehensive income, except for the recognition of impairment gains or losses, interest revenue (including transaction costs by applying the effective interest method), gains or losses arising on de-recognition and foreign exchange gains and losses which are recognised in the income statement. When the financial asset is derecognised, the cumulative fair value gain or loss previously recognised in other comprehensive income is reclassified to the income statement. – Equity investments where the Group has irrevocably elected to present fair value gains and losses on revaluation in other comprehensive income. The election can be made for each individual investment; however it is not applicable to equity investments held for trading. Fair value gains or losses on revaluation of such equity investments, including any foreign exchange component, are recognised in other comprehensive income. When the equity investment is derecognised, there is no reclassification of fair value gains or losses previously recognised in other comprehensive income to the income statement. Dividends are recognised in the income statement when the right to receive payment is established. 1 Principal accounting policies continued (c) Financial assets held at fair value through profit or loss (FVPL) This classification applies to the following financial assets. In all cases, transaction costs are immediately expensed to the income statement. – Debt instruments that do not meet the criteria of amortised cost or fair value through other comprehensive income. The Group has a significant proportion of trade receivables with embedded derivatives for provisional pricing. These receivables are generally held to collect but do not meet the SPPI criteria and as a result must be held at FVPL. Subsequent fair value gains or losses are taken to the income statement. In addition, trade receivable invoices for certain customers which are routinely factored, in order to address credit risk and support value delivery through timelier realisation, are held at FVPL. – Equity investments which are held for trading or where the FVOCI election has not been applied. All fair value gains or losses and related dividend income are recognised in the income statement. – Derivatives which are not designated as a hedging instrument. All subsequent fair value gains or losses are recognised in the income statement. (ii) Financial liabilities Borrowings and other financial liabilities (including trade payables but excluding derivative liabilities) are recognised initially at fair value, net of transaction costs incurred, and are subsequently measured at amortised cost. The Group participates in supply chain finance arrangements whereby vendors may elect to receive early payment of their invoice from a third-party bank by factoring their receivable from Rio Tinto. These arrangements do not modify the terms of the original liability with respect to either counterparty terms, settlement date or amount due. Utilisation of the early settlement facility is voluntary and at the vendors' discretion on an invoice-by-invoice basis. Financial liabilities subject to supply chain finance therefore continue to be classified as trade payables. At 31 December 2020, trade payables included US$551 million (2019: US$573 million) subject to early settlement election by vendors. (iii) Impairment of financial assets A forward-looking expected credit loss (ECL) review is required for: debt instruments measured at amortised cost or held at fair value through other comprehensive income; loan commitments and financial guarantees not measured at fair value through profit or loss; lease receivables; and trade receivables that give rise to an unconditional right to consideration. As permitted by IFRS 9, the Group applies the “simplified approach” to trade receivable balances and receivables relating to net investment in finance leases and the “general approach” to all other financial assets. The general approach incorporates a review for any significant increase in counterparty credit risk since inception. The ECL reviews include assumptions about the risk of default and expected loss rates. For trade receivables and receivables relating to net investment in finance leases, the assessment takes into account the use of credit enhancements, for example, letters of credit. Impairments for undrawn loan commitments are reflected as a provision. (iv) Derivatives and hedge accounting The Group applies the hedge accounting requirements under IFRS 9 and its hedging activities are discussed in note 29 with movements on hedging reserves disclosed in note 28. Where applicable, the Group may defer the costs of hedging including currency basis spreads, forward points and the time value of options.
Share-based payments	(r) Share-based payments (note 41) The fair value of the Group’s share plans is recognised as an expense over the expected vesting period with an offset to retained earnings for Rio Tinto plc plans and to other reserves for Rio Tinto Limited plans. The Group uses fair values provided by independent actuaries calculated using either a lattice-based option valuation model or a Monte Carlo simulation model. The terms of each plan are considered at the balance sheet date to determine whether the plan should be accounted for as equity-settled or cash-settled. The Group does not operate any plans as cash-settled. However, the Performance Share Plan can, at the discretion of the directors, offer employees an equivalent amount in cash. This is not standard practice. In some jurisdictions, employees are granted cash- settled awards where equity-settled awards are prohibited by local laws and regulations. The value of these awards is immaterial.
Share capital	(s) Share capital (notes 26 and 27) Ordinary shares are classified as equity. Incremental costs directly attributable to the issuance of new shares are shown in equity as a deduction, net of tax, from the proceeds.
Segment reporting	(t) Segment reporting (notes 2 and 3)

Operating segments (Tables)

Operating segments (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of operating segments [abstract]
Summary of operating segments	Gross product sales 2020 US$m 2019 US$m 2018 US$m Iron Ore 27,508 24,075 18,731 Aluminium 9,314 10,340 12,191 Copper & Diamonds 5,428 5,815 6,468 Energy & Minerals 5,014 5,150 5,451 Reportable segments total 47,264 45,380 42,841 Other Operations 18 18 9 Inter-segment transactions (264) (31) (15) Product group total 47,018 45,367 42,835 Share of equity accounted unit sales and adjustments for intra-subsidiary/equity accounted units sales (2,407) (2,202) (2,313) Consolidated sales revenue per income statement 44,611 43,165 40,522 Gross product sales includes the Group’s proportionate share of product sales by equity accounted units (after adjusting for sales to subsidiaries) of US$2,441 million (2019: US$2,234 million; 2018: US$2,354 million) which are not included in consolidated sales revenue. Consolidated sales revenue includes subsidiary sales of US$34 million (2019: US$32 million; 2018: US$41 million) to equity accounted units which are not included in gross product sales. Capital expenditure 2020 US$m 2019 US$m 2018 US$m Iron Ore 2,941 1,741 1,302 Aluminium 1,085 1,456 1,373 Copper & Diamonds 1,864 2,087 2,150 Energy & Minerals 428 551 442 Reportable segments total 6,318 5,835 5,267 Other Operations 2 (4) 12 Product group total 6,320 5,831 5,279 Other items 79 64 65 Less: capital expenditure of equity accounted units (255) (456) (500) Capital expenditure per financial information by business unit 6,144 5,439 4,844 Add back: proceeds from disposal of property, plant and equipment (a) 45 49 586 Capital expenditure per cash flow statement 6,189 5,488 5,430 (a) In 2018, proceeds from disposal of property, plant and equipment included US$508 million received on the sale of surplus land at Kitimat. Capital expenditure for reportable segments comprises the net cash outflow on purchases less disposals of property, plant and equipment, capitalised evaluation costs and purchases less disposals of other intangible assets. The details provided include 100% of subsidiaries’ capital expenditure and Rio Tinto’s share of the capital expenditure of joint operations and equity accounted units. Depreciation and amortisation 2020 US$m 2019 US$m 2018 US$m Iron Ore 1,838 1,723 1,702 Aluminium 1,191 1,312 1,122 Copper & Diamonds 1,153 1,320 1,317 Energy & Minerals 392 428 455 Reportable segments total 4,574 4,783 4,596 Other Operations 199 177 26 Product group total 4,773 4,960 4,622 Other items 82 77 43 Less: depreciation and amortisation of equity accounted units (576) (653) (650) Depreciation and amortisation per note 4 4,279 4,384 4,015 Product group depreciation and amortisation for reportable segments include 100% of subsidiaries’ depreciation and amortisation and Rio Tinto’s share of the depreciation and amortisation of equity accounted units. Rio Tinto’s share of the depreciation and amortisation charge of equity accounted units is deducted to arrive at depreciation and amortisation as shown in note 4. These figures do not include impairment charges and reversals, which are excluded from underlying earnings. Tax charge/(credit) 2020 US$m 2019 US$m 2018 US$m Iron Ore 5,035 4,198 2,830 Aluminium 320 211 532 Copper & Diamonds (238) 65 118 Energy & Minerals 360 411 500 Reportable segments total 5,477 4,885 3,980 Other Operations (7) (51) (51) Inter-segment transactions (24) (2) — Product group total 5,446 4,832 3,929 Other items (179) (67) (276) Exploration and evaluation not attributed to product groups (34) (83) (38) Net finance costs (38) (144) (174) 5,195 4,538 3,441 Tax (credit)/charge excluded from underlying earnings (204) (391) 801 Taxation per income statement 4,991 4,147 4,242 Tax charge/(credit) excludes amounts relating to equity accounted units. Further information on the tax charge/(credit) excluded from underlying earnings is provided in the section “Underlying earnings”, below. Underlying EBITDA 2020 US$m 2019 US$m 2018 US$m Iron Ore 18,837 16,098 11,378 Aluminium 2,152 2,285 3,095 Copper & Diamonds 2,172 2,073 2,776 Energy & Minerals 1,646 1,762 2,140 Reportable segments total 24,807 22,218 19,389 Other Operations — (77) (70) Inter-segment transactions (94) (9) — Product group total 24,713 22,132 19,319 Central pension costs, share-based payments and insurance 72 59 (128) Restructuring, project and one-off costs (133) (183) (272) Central costs (500) (496) (552) Exploration and evaluation not attributed to product groups (250) (315) (231) Underlying EBITDA 23,902 21,197 18,136 Impairment charges (1,272) (3,487) (132) Gains/(losses) on embedded commodity derivatives not qualifying for hedge accounting (including exchange) 6 (260) 279 Net (losses)/gains on consolidation and disposal of interests in businesses — (291) 4,622 Change in closure estimates (non-operating and fully impaired sites) (401) — (376) Gain on sale of wharf and land in Kitimat, Canada — — 602 Change in other exclusions — (171) — Items excluded from underlying EBITDA (1,667) (4,209) 4,995 Depreciation and amortisation in subsidiaries and equity accounted units (4,650) (4,925) (4,559) Taxation and finance items in equity accounted units (443) (296) (372) Finance items (1,751) (648) (33) Profit before taxation 15,391 11,119 18,167 2 Operating segments continued Underlying earnings 2020 US$m 2019 US$m 2018 US$m Iron Ore 11,398 9,638 6,531 Aluminium 471 599 1,347 Copper & Diamonds 763 554 1,054 Energy & Minerals 577 611 995 Reportable segments total 13,209 11,402 9,927 Other Operations (54) (89) (102) Inter-segment transactions (32) (3) — Product group total 13,123 11,310 9,825 Central pension costs, share-based payments and insurance 81 60 (90) Restructuring, project and one-off costs (108) (94) (190) Central costs (418) (550) (410) Exploration and evaluation not attributed to product groups (216) (231) (193) Net finance costs (14) (122) (134) Underlying earnings 12,448 10,373 8,808 Items excluded from underlying earnings (2,679) (2,363) 4,830 Net earnings attributable to owners of Rio Tinto per income statement 9,769 8,010 13,638 Reconciliation of underlying earnings to net earnings Pre-tax(h) Taxation 2020 US$m Non-controlling interests 2020 US$m Net amount 2020 US$m Net amount 2019 US$m Net amount 2018 US$m Underlying earnings 18,282 (5,195) (639) 12,448 10,373 8,808 Items excluded from underlying earnings Impairment charges (note 6) (1,243) 128 — (1,115) (1,658) (104) Net (losses)/gains on consolidation and disposal of interests in businesses (a) — — — — (291) 3,996 Exchange and derivative gains/(losses): – Exchange (losses)/gains on external net debt, intragroup balances and derivatives (b) (1,138) 5 8 (1,125) 51 550 – Losses on currency and interest rate derivatives not qualifying for hedge accounting (c) (142) (19) 4 (157) (59) (48) – Gains/(losses) on embedded commodity derivatives not qualifying for hedge accounting (d) 33 (10) (5) 18 (192) 202 Net losses from movements to closure estimates (non-operating and fully impaired sites) (e) (401) 100 1 (300) — (335) Gain relating to surplus land at Kitimat (f) — — — — — 569 Other exclusions (g) — — — — (214) — Total excluded from underlying earnings (2,891) 204 8 (2,679) (2,363) 4,830 Net earnings 15,391 (4,991) (631) 9,769 8,010 13,638 (a) In 2019, the net loss mainly related to the disposal of our entire 68.62% stake in Rössing Uranium on 16 July 2019 for which we recorded a pre-tax loss of US$289 million (US$289 million net of tax). In 2018, the net gain related mainly to the sales of the Hail Creek coal mine and the Kestrel underground coal mine, which both completed on 1 August 2018, the sale of the Dunkerque aluminium smelter on 14 December 2018 and the sale of Grasberg on 21 December 2018. The net gain in 2018 also includes a gain on consolidation recognised on the formation on 10 May 2018 of ELYSIS, a new joint venture to develop a carbon-free smelting process. Refer to note 36 f or further details in respect of these transactions. (b) Exchange losses on external net debt and intragroup balanc es comprise post-tax foreign exchange losses on intragroup balances of US$1,330 million partially offset by post-tax gains of US$205 million on external net debt, primarily as a result of strengthening of the Australian dollar against the US dollar. In 2019, exchange gains on external net debt and intragroup balances comprise post-tax foreign exchange gains on net debt of US$60 million and post-tax losses of US$9 million on intragroup balances, primarily as a result of the Canadian dollar strengthening against the US dollar. From 1 January 2019, all foreign exchange gains and losses relating to net debt are excluded fro m underlying earnings. In 2018 and previous years, foreign exchange gains and losses on non-US dollar cash held in US dollar functional currency entities was included within underlying earnings. The impact of this change on the reported 2018 comparatives is insignificant, and therefore the comparatives have not been restated. In 2018 the net exchange gains comprise post-tax foreign exchange losses of US$386 million on US dollar denominated net debt and US$936 million gains on intragroup balances. (c) Valuation changes on currency and interest rate derivatives, which are ineligible for hedge accounting, other than those embedded in commercial contracts, and the currency revaluation of embedded US dollar derivatives contained in contracts held by entities whose functional currency is not the US dollar. (d) Valuation changes on derivatives, embedded in commercial contracts, that are ineligible for hedge accounting, but for which there will be an offsetting change in future Group earnings. Mark-to-market movements on commodity derivatives entered into with the commercial objective of achieving spot pricing for the underlying transaction at the date of settlement are included in underlying earnings. (e) I n 2020 the pre-feasibility study for the Gove refinery closure was completed, resulting in an increase to the closure provision. As a non-operating asset, this increase was recognised through the income statement. Also in 2020, the feasibility study for the Argyle mine closure was completed, resulting in a decrease to the closure provision. As the assets at Argyle had previously been fully impaired this decrease was recognised through the income statement, in line with previous movements to the closure provision. This amount also includes an increase in Diavik's closure provision to reflect the latest findings from the ongoing Pre-Feasibility Study, recognised through the incomes statement as Diavik was fully impaired during the year. It also includes the net earnings impact ( US$138 million loss) in respect of increases to these closure provisions following a reduction to the closure discount rate to 1.5% . In 2018, the pre-feasibility study for the Argyle mine closure was completed, resulting in an increase to the closure provision. As the assets at Argyle had previously been fully impaired, this increase was not capitalised and was instead recognised in the income statement. Also in 2018, the feasibility study for the closure of the Ranger Project Area at Energy Resources of Australia (ERA) was finalised, resulting in an increase to the closure provision. As the assets of ERA had been fully impaired, this increase was recognised in the income statement. The charge was excluded from underlying earnings. (f) In November 2018, Rio Tinto completed the lease and sale of a wharf and land in Kitimat. The resulting gain on disposal of property, plant and equipment and other income were both excluded from underlying earnings on the grounds of materiality. (g) In 2019, other exclusions included provisions for obligations in respect of legacy operations of US$246 million (loss of US$233 million after tax), partially offset by the write-back of a net realisable value provision in respect of low grade stockpile inventories at Oyu Tolgoi of US$75 million (gain of US$19 million after tax and non-controlling interests). As a result of increased uncertainty over timing of production from the Oyu Tolgoi underground project (refer to note 6), we expected to utilise low grade stockpiles sooner than previously forecast. This was excluded from underlying earnings, consistent with the related impairment charge recognised in 2019.

Operating segments - addition_2

Operating segments - additional information (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of operating segments [abstract]
Summary of geographical location sales revenue and non-current assets other than excluded items	Consolidated sales revenue by destination (a) 2020 % 2020 US$m China 58.1 51.3 44.6 25,940 22,135 18,061 Asia (excluding China and Japan) 10.2 10.6 11.5 4,536 4,558 4,665 United States of America 10.9 14.2 15.6 4,867 6,125 6,337 Japan 7.5 8.9 9.6 3,354 3,855 3,873 Europe (excluding UK) 5.9 6.0 9.3 2,623 2,610 3,788 Canada 2.9 3.3 3.3 1,289 1,478 1,330 Australia 1.7 1.7 1.8 745 737 720 UK 0.5 0.6 0.7 242 248 264 Other countries 2.3 3.4 3.6 1,015 1,419 1,484 Consolidated sales revenue 100 100 100 44,611 43,165 40,522 (a) Consolidated sales revenue by geographical destination is based on the ultimate country of destination of the product, if known. If the eventual destination of the product sold through traders is not known then revenue is allocated to the location of the product at the time when control is transferred. Rio Tinto is domiciled in both the UK and Australia. Non-current assets other than excluded items (a) The total of non-current assets other than excluded items is shown by location below. 2020 US$m 2019 US$m Australia 32,290 27,944 Canada 14,666 14,644 Mongolia 10,285 9,187 United States of America 6,090 5,459 Africa 3,294 3,583 South America 2,718 2,652 Europe (excluding France and the UK) 157 193 UK 117 158 France 55 64 Other countries 1,008 1,314 Total non-current assets other than excluded items 70,680 65,198 Non-current assets excluded from analysis above: Deferred tax assets 3,385 3,102 Other financial assets (b) 829 635 Quasi equity loans to equity accounted units (b) 112 113 Tax recoverable 4 5 Receivables and other assets 1,525 1,446 Total non-current assets per balance sheet 76,535 70,499 (a) Allocation of non-current assets by country is based on the location of the business units holding the assets. It includes investments in equity accounted units totalling US$3,652 million (2019: US$3,858 million) which represents the Group’s share of net assets excluding quasi equity loans shown separately above. (b) Loans to equity accounted units comprise quasi equity loans of US$112 million (2019: US$113 million) included in “Investments in equity accounted units” on the face of the balance sheet and non-current non-quasi equity loans of US$1 million (2019: US$39 million) shown within “Other financial assets”.
Consolidated sales revenue by product	Consolidated sales revenues of the Group are derived from the following products sold to external customers: Revenue from contracts with customers 2020 US$m Other revenue (a) 2020 US$m Consolidated sales revenue 2020 US$m Iron ore 28,202 1,000 29,202 Aluminium, Alumina and Bauxite 9,092 54 9,146 Copper 1,721 64 1,785 Industrial minerals 2,054 (3) 2,051 Gold 471 6 477 Diamonds 459 — 459 Uranium (b) 299 — 299 Other (b) 1,194 (2) 1,192 Consolidated sales revenue 43,492 1,119 44,611 Share of equity accounted unit sales and intra-subsidiary/equity accounted unit sales 2,407 Gross product sales 47,018 Revenue from contracts Other revenue (a) 2019 US$m Consolidated sales revenue Other revenue (a) 2018 US$m Iron ore 25,516 229 25,745 19,888 (21) 19,867 Aluminium, Alumina and Bauxite 10,207 (32) 10,175 12,041 (22) 12,019 Copper 2,030 (7) 2,023 2,420 (32) 2,388 Coal — — — 986 3 989 Industrial minerals 2,251 (12) 2,239 2,168 — 2,168 Gold 667 2 669 869 — 869 Diamonds 619 — 619 695 — 695 Uranium (b) 375 — 375 415 — 415 Other (b) 1,322 (2) 1,320 1,112 — 1,112 Consolidated sales revenue 42,987 178 43,165 40,594 (72) 40,522 Share of equity accounted unit sales and intra-subsidiary/equity accounted unit sales 2,202 2,313 Gross product sales 45,367 42,835 (a) Certain of the Group's products may be provisionally priced at the date revenue is recognised. The change in value of the provisionally priced receivables is based on relevant forward market prices and is included in “Other revenue” above.

Net operating costs (excludin_2

Net operating costs (excluding items shown separately) (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Net Operating Costs Excluding Items Shown Separately [Abstract]
Summary of net operating costs (excluding items shown separately)	Note 2020 US$m 2019 US$m 2018 US$m Raw materials, consumables, repairs and maintenance 8,490 9,485 10,613 Amortisation of intangible assets 13 161 133 133 Depreciation of property, plant and equipment 14 4,118 4,251 3,882 Employment costs 5 4,770 4,522 4,728 Shipping and other freight costs (a) 2,088 2,257 2,580 (Increase)/decrease in finished goods and work in progress (47) 42 (186) Royalties 2,763 2,501 2,117 Amounts charged by equity accounted units (b) 958 1,136 1,200 Net foreign exchange losses/(gains) 300 (52) (56) Other external costs (a) 3,083 3,627 3,184 Loss/(gain) on sale of property, plant and equipment (c) 50 31 (506) Provisions (including exchange differences on provisions) 25 894 753 1,011 Research and development 45 45 45 Costs included above capitalised or shown separately as exploration and evaluation costs (d) (708) (651) (589) Other operating income (711) (773) (1,041) Net operating costs (excluding items shown separately) 26,254 27,307 27,115 (a) In 2020, other external costs include US$314 million (2019: US$327 million) of short-term lease costs and US$30 million (2019: US$15 million) of variable lease costs recognised in the income statement in accordance with IFRS 16 “Leases”. Refer to note 22. In 2018, net operating costs included US$787 million of operating lease expenses under IAS 17 “Leases”. Costs for leases of dry bulk vessels (which included costs for crewing services) were included within “Shipping and other freight costs” and other lease costs were included within “Other external costs”. (b) Amounts charged by equity accounted units relate to toll processing and also include purchases from equity accounted units of bauxite and aluminium which are then processed by the product group or sold to third parties. Generally, purchases are in proportion to the Group’s share of the equity accounted unit but in 2020, US$129 million (2019: US$291 million; 2018: US$332 million) related to purchases of the other investors’ share of production. (c) In 2018, includes a US$549 million pre-tax gain on the sale of property, plant and equipment at Kitimat. Refer to note 2. (d) In 2020, US$537 million (2019: US$469 million; 2018: US$400 million) of operating costs were capitalised and US$171 million (2019: US$182 million; 2018: US$189 million) of costs were shown separately within "Exploration and evaluation costs" in the Group income statement.

Employment costs (Tables)

Employment costs (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Employee Cost Explanatory [Abstract]
Summary of employment costs	Note 2020 US$m 2019 US$m 2018 US$m Total employment costs – Wages and salaries 4,141 3,923 4,154 – Social security costs 330 328 336 – Net post-retirement charge 42 469 384 532 – Share-based payment charge 41 138 123 122 5,078 4,758 5,144 Less: charged within provisions (a) 25 (308) (236) (416) Total employment costs 4 4,770 4,522 4,728 (a) Amounts included above relate to provisions for pensions, post-retirement healthcare, long service leave and other employee entitlements. These are included in “Provisions (including exchange differences on provisions)” in note 4.

Impairment charges - (Tables)

Impairment charges - (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of impairment loss recognised or reversed for cash-generating unit [abstract]
Summary of impairment charges	Note Pre-tax amount 2020 US$m Taxation 2020 US$m Non-controlling interest 2020 US$m Net amount 2020 US$m Pre-tax amount 2019 US$m Pre-tax amount 2018 US$m Aluminium – Pacific Aluminium (489) 17 — (472) — Aluminium – Sohar (220) — — (220) — — Aluminium – ISAL (93) (38) — (131) (109) (123) Copper & Diamonds – Diavik (441) 149 — (292) — Copper & Diamonds – Oyu Tolgoi — — — — (2,240) — Aluminium - Yarwun alumina refinery — — — — (1,138) — Energy & Minerals – Rössing — — — — — (9) Total impairment charge (1,243) 128 — (1,115) (3,487) (132) Allocated as: Intangible assets 13 (4) (1) (2) Property, plant and equipment 14 (900) (3,486) (130) Investment in equity accounted units ("EAUs") (339) — — Total impairment charge (1,243) (3,487) (132) Comprising: Impairment charges of consolidated balances (904) (3,487) (132) Impairment charges related to EAUs (pre-tax) (368) — — Total impairment charge (1,272) (3,487) (132) Taxation (including related to EAUs) 157 323 25 Non-controlling interests — 1,506 3 Total impairment in the income statement (1,115) (1,658) (104)

Share of profit after tax of _2

Share of profit after tax of equity accounted units (Tables)	12 Months Ended
	Dec. 31, 2020
Share of profit (loss) of associates and joint ventures accounted for using equity method [abstract]
Summary of share of profit after tax of equity accounted units	2020 US$m 2019 US$m 2018 US$m Sales revenue: Rio Tinto share (a) 2,490 2,358 2,497 Operating costs (1,439) (1,812) (1,656) Profit before finance items and taxation 1,051 546 841 Finance items (59) (65) (69) Share of profit after tax of equity accounted units 23 10 14 Profit before taxation 1,015 491 786 Taxation (363) (190) (273) Profit for the year (Rio Tinto share) 652 301 513

Finance income and finance co_2

Finance income and finance costs (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Finance Income Expense Explanatory [Abstract]
Summary of Finance Income and Finance Cost	Note 2020 US$m 2019 US$m 2018 US$m Finance income from equity accounted units 4 4 7 Other finance income (including bank deposits, net investment in leases, and other financial assets) 137 296 242 Total finance income 141 300 249 Interest on: – Financial liabilities at amortised cost (excluding lease liabilities) and associated derivatives (561) (816) (775) – Lease liabilities (50) (55) (2) Fair value movements: – Bonds designated as hedged items in fair value hedges (284) (185) 96 – Derivatives designated as hedging instruments in fair value hedges 287 181 (73) Loss on early redemption of bonds (a) — — (94) Amounts capitalised 14 340 321 296 Total finance costs (268) (554) (552) (a) In 2018 we completed a bond buy-back programme of US$1.9 billion (nominal value). Loss on early redemption of bonds included a premium charge of US$72 million, unamortised debt issuance costs and fees of US$9 million, the write-off of the fair value hedge adjustment of US$16 million and the reclassification of a gain out of the cost of hedging reserve of US$3 million. Net interest paid in the Group cash flow statement included the payment of the premiums and the accelerated interest associated with the bond redemptions (US$80 million). There was no bond buy-back programme in 2020 or 2019.

Taxation (Tables)

Taxation (Tables)	12 Months Ended
	Dec. 31, 2020
Major components of tax expense (income) [abstract]
Summary of taxation charge	Taxation charge Note 2020 US$m 2019 US$m 2018 US$m – Current 5,169 4,436 3,726 – Deferred 17 (178) (289) 516 Total taxation charge 4,991 4,147 4,242
Summary of prima facie tax reconciliation	Prima facie tax reconciliation 2020 US$m 2019 US$m 2018 US$m Profit before taxation 15,391 11,119 18,167 Deduct: share of profit after tax of equity accounted units (a) (652) (301) (513) Add: impairment after tax of investments in equity accounted units (a) 339 — — Parent companies' and subsidiaries' profit before tax 15,078 10,818 17,654 Prima facie tax payable at UK rate of 19% (2019: 19%; 2018: 19%) 2,865 2,055 3,354 Higher rate of taxation on Australian underlying earnings 1,779 1,495 1,106 Impact of items excluded in arriving at underlying earnings (b) : – Impairment charges (c) 44 340 — – Net gains and losses on consolidation and disposal of interests in businesses — 55 (251) – Exchange and gains/losses on derivatives 260 (22) 32 – Losses from increases to closure estimates (non-operating and fully impaired sites) (24) — 30 – Gain relating to surplus land at Kitimat — — (81) – Other exclusions — 38 — Impact of changes in tax rates and laws — 1 47 Other tax rates applicable outside the UK and Australia on underlying earnings (80) (110) (47) Resource depletion and other depreciation allowances (34) (57) (46) Recognition of previously unrecognised deferred tax assets (d) (182) — — Write-down of previously recognised deferred tax assets (e) 173 42 13 Amounts under/(over) provided in prior years 9 83 (108) Other items (f) 181 227 193 Total taxation charge (a) 4,991 4,147 4,242 (a) This tax reconciliation relates to the Group's parent companies, subsidiaries and joint operations, and excludes equity accounted units. The Group's share of profit of equity accounted units is net of tax charges of US$363 million (2019: US$190 million; 2018: US$273 million). Impairment after tax of investments in equity accounted units is net of tax credits of US$29 million (2019: US$nil; 2018: US$nil). (b) The impact for each item includes the effect of tax rates applicable outside the UK. (c) The tax impact of impairments includes the write-down of deferred tax assets at ISAL and NZAS and non-recognition of deferred tax on those impairments. The tax impact also includes recognition at local tax rates of deferred tax assets arising on the impairments of Bell Bay, Gladstone Power Station and Diavik. In the comparative period to 31 December 2019, the tax impact of impairment includes the write down of deferred tax assets in respect of prior year tax losses in Mongolia and recognition of deferred tax on impaired assets. Refer to note 6. (d) The recognition of previously unrecognised deferred tax assets relates to the recognition of prior year deferred tax assets on losses and on impaired assets at Oyu Tolgoi due to improved deferred tax asset recovery expectations. (e) Write down of previously recognised deferred tax assets relates primarily to the partial de-recognition of deferred tax assets in our Australian Aluminium business.
Summary of tax relating to components of other comprehensive income or loss	2020 US$m 2019 US$m 2018 US$m Tax on fair value movements: – Cash flow hedge fair value gains 3 (6) (54) Tax credit/(charge) on actuarial gains and losses on post-retirement benefit plans 112 83 (271) Tax relating to components of other comprehensive income/(loss) for the year (a) 115 77 (325) (a) This comprises a deferred tax credit of US$115 million (2019: credit of US$77 million; 2018: charge of US$325 million) and a current tax charge of US$nil (2019: US$nil; 2018: US$nil), see note 17.

Earnings per ordinary share (Ta

Earnings per ordinary share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings per share [abstract]
Summary of earnings (loss) per ordinary shares	2020 Earnings US$m 2020 Weighted average number of shares (millions) 2020 Per share amount (cents) 2019 Earnings US$m 2019 Weighted average number of shares (millions) 2019 Per share amount (cents) Basic earnings per share attributable to ordinary shareholders of Rio Tinto (a) 9,769 1,617.4 604.0 8,010 1,630.1 491.4 Diluted earnings per share attributable to ordinary shareholders of Rio Tinto (b) 9,769 1,628.6 599.8 8,010 1,642.1 487.8 2018 Earnings US$m 2018 Weighted average number of shares (millions) 2018 Per share amount (cents) Basic earnings per share attributable to ordinary shareholders of Rio Tinto (a) 13,638 1,719.3 793.2 Diluted earnings per share attributable to ordinary shareholders of Rio Tinto (b) 13,638 1,731.7 787.6 (a) The weighted average number of shares is calculated as the average num ber of Rio Tinto plc shares outstanding not held as treasury shares of 1,246.5 million ( 2019 : 1,259.4 million ; 2018 : 1,312.7 million ) plus the average number of Rio Tinto Limited shares outstanding of 370.9 million ( 2019 : 370.7 million ; 2018 : 406.6 million ) over the relevant period. There were no cross holdings of shares between Rio Tinto Limited and Rio Tinto plc at 31 December 2020 ( 31 December 2019 : nil ). (b) For the purposes of calculating diluted earnings per share, the effect of dilutive securities of 11.2 million s hares in 2020 (2019: 12.0 million; 2018: 12.4 million) is added to the weighted average number of shares described in (a) above. This effect is calculated under the treasury stock method, in accordance with IAS 33 “Earnings per Share”. The Group’s only potential dilutive ordinary shares are share options for which terms and conditions are described in note 41.

Dividends (Tables)

Dividends (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Dividends [Abstract]
Summary of dividends paid	2020 US$m 2019 US$m 2018 US$m Rio Tinto plc previous year final dividend paid 2,783 2,245 2,446 Rio Tinto plc previous year special dividend paid — 3,032 — Rio Tinto plc interim dividend paid 1,937 1,930 1,666 Rio Tinto plc interim special dividend paid — 780 — Rio Tinto Limited previous year final dividend paid 857 666 731 Rio Tinto Limited previous year special dividend paid — 900 — Rio Tinto Limited interim dividend paid 555 556 513 Rio Tinto Limited interim special dividend paid — 225 — Dividends paid during the year 6,132 10,334 5,356 Dividends per share: paid during the year 386.0 c 635.0 c 307.0 c Final dividends per share: proposed in the announcement of the results for the year 309.0 c 231.0 c 180.0 c Special dividends per share: proposed in the announcement of the results for the year 93.0 c — 243.0 c
Summary of dividends per share	Dividends per share 2020 Dividends per share 2019 Dividends per share 2018 Rio Tinto plc previous year final (pence) 177.47 p 135.96 p 129.43 p Rio Tinto plc previous year special (pence) — 183.55 p — Rio Tinto plc interim (pence) 119.74 p 123.32 p 96.82 p Rio Tinto plc interim special (pence) — 49.82 p — Rio Tinto Limited previous year final – fully franked at 30% (Australian cents) 349.74 c 250.89 c 228.53 c Rio Tinto Limited previous year special – fully franked at 30% (Australian cents) — 338.70 c — Rio Tinto Limited interim – fully franked at 30% (Australian cents) 216.47 c 219.08 c 170.84 c Rio Tinto Limited interim special – fully franked at 30% (Australian cents) — 88.50 c —
Summary of number of shares dividend distributed	Number of shares 2020 (millions) Number of shares 2019 (millions) Number of shares 2018 (millions) Rio Tinto plc previous year final 1,246.4 1,265.0 1,334.8 Rio Tinto plc previous year special N/A 1,265.0 N/A Rio Tinto plc interim 1,246.5 1,256.4 1,308.4 Rio Tinto plc interim special N/A 1,256.4 N/A Rio Tinto Limited previous year final 371.2 371.2 412.4 Rio Tinto Limited previous year special N/A 371.2 N/A Rio Tinto Limited interim 371.2 371.2 412.4 Rio Tinto Limited interim special N/A 371.2 N/A

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill [Abstract]
Summary of goodwill	2020 US$m 2019 US$m Net book value At 1 January 922 912 Adjustment on currency translation 24 10 At 31 December 946 922 – cost 17,341 16,926 – accumulated impairment (16,395) (16,004) At 1 January – cost 16,926 15,861 – accumulated impairment (16,004) (14,949) At 31 December, goodwill has been allocated as follows: 2020 US$m 2019 US$m Net book value Richards Bay Minerals 468 487 Pilbara 383 349 Dampier Salt 95 86 946 922
Key assumptions calculation of fair value less costs of disposal	The key assumptions to which the calculation of FVLCD for Richards Bay Minerals is most sensitive and the corresponding decrease in FVLCD are set out below: US$m 5% decrease in the titanium slag price 182 1% increase in the discount rate applied to post-tax cash flows 213 10% strengthening of the South African rand 393

Intangible assets (Tables)

Intangible assets (Tables)	12 Months Ended
	Dec. 31, 2020
Intangible Assets [Abstract]
Summary of intangible assets	Year ended 31 December 2020 Exploration and evaluation (a) US$m Trademarks, patented and Contract based intangible assets (b) US$m Other Total Net book value At 1 January 2020 173 44 1,947 473 2,637 Adjustment on currency translation 17 3 56 35 111 Expenditure during the year 87 — — 69 156 Amortisation for the year (c) — (14) (8) (139) (161) Impairment charges (d) — — — (4) (4) Disposals, transfers and other movements (6) — (1) 23 16 At 31 December 2020 271 33 1,994 457 2,755 – cost 2,415 232 3,070 1,710 7,427 – accumulated amortisation and impairment (2,144) (199) (1,076) (1,253) (4,672) Year ended 31 December 2019 Exploration and evaluation (a) US$m Trademarks, patented and Contract based intangible assets (b) US$m Other Total Net book value At 1 January 2019 233 59 1,982 505 2,779 Adjustment on currency translation (1) (1) 74 (1) 71 Expenditure during the year 57 — — 34 91 Amortisation for the year (c) — (14) (8) (111) (133) Impairment charges (d) — — — (1) (1) Disposals, transfers and other movements (e) (116) — (101) 47 (170) At 31 December 2019 173 44 1,947 473 2,637 – cost 2,306 214 3,002 1,516 7,038 – accumulated amortisation and impairment (2,133) (170) (1,055) (1,043) (4,401) 13 Intangible assets continued (a) Exploration and evaluation assets’ useful lives are not determined until transferred to property, plant and equipment. (b) The Group benefits from certain intangible assets acquired with Alcan, including power supply contracts, customer contracts and water rights. The water rights are expected to contribute to the efficiency and cost effectiveness of operations for the foreseeable future; accordingly, these rights are considered to have indefinite lives and are not subject to amortisation but are tested annually for impairment. These water rights constitute the majority of the amounts in “Contract based intangible assets”. The remaining carrying value of the water rights of US$1,798 million as at 31 December 2020 (31 December 2019: US$1,759 million) relates wholly to the Quebec smelters cash-generating unit (CGU). The Quebec smelters CGU was tested for impairment by reference to fair value less cost of disposal (FVLCD) using discounted cash flows, which is in line with the policy set out in note 1(i). The recoverable amount of the Quebec smelters is classified as level 3 under the fair value hierarchy. In arriving at FVLCD, post-tax cash flows expressed in real terms have been estimated over the expected useful economic lives of the underlying smelting assets and discounted using a real post-tax discount rate of 6.6% (2019: 6.6%). T he recoverable amounts were determined to be significantly in excess of carrying value, and there are no reasonably possible changes in key assumptions that would cause the remaining water rights to be impaired. (c) Finite life intangible assets are amortised over their useful economic lives on a straight line or units of production basis, as appropriate. Where amortisation is calculated on a straight line basis, the following useful lives have been determined: Trademarks, patented and non-patented technology: Trademarks: 14 to 20 years Patented and non-patented technology: ten to 20 years Contract-based intangible assets: Power contracts/water rights: two to 45 years Other purchase and customer contracts: five to 15 years Other intangible assets: Internally generated intangible assets and computer software: two to five years Other intangible assets: two to 20 years (d) Impairment charges in 2020 relate to the Diavik diamond mine. Impairment charges in 2019 relate to the ISAL smelter. See note 6.
Summary of exploration and evaluation expenditure	The charge for the year and the net amount of intangible assets capitalised during the year are as follows: 2020 US$m 2019 US$m 2018 US$m Net expenditure in the year (net of cash proceeds of US$1 million (2019: US$10 million; 2018: US$233 million) on disposal of undeveloped projects) (711) (671) (345) Non-cash movements and non-cash proceeds on disposal of undeveloped projects — — 45 Amount capitalised during the year 87 57 90 Net charge for the year (624) (614) (210) Reconciliation to income statement: Exploration and evaluation costs (625) (624) (488) Profit relating to interests in undeveloped projects (a) 1 10 278 Net charge for the year (624) (614) (210) (a) During 2018, profit relating to interests in undeveloped properties related to the gains on the sales of Valeria (US$83 million) and Winchester South (US$195 million) undeveloped properties which were included within underlying earnings.

Property, plant and equipment (

Property, plant and equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, plant and equipment [abstract]
Schedule of Property, Plant and Equipment, Owned and Leased Assets	Property, plant and equipment comprises owned and leased assets. 2020 US$m 2019 US$m Property, plant and equipment – owned 62,007 56,307 Right of use assets – leased 875 1,065 Net book value 62,882 57,372
Summary of property, plant and equipment	Year ended 31 December 2020 Note Mining properties and leases (a) US$m Land and buildings US$m Plant Capital Total Net book value At 1 January 2020 10,402 6,403 31,491 8,011 56,307 Adjustment on currency translation (b) 457 307 1,758 366 2,888 Adjustments to capitalised closure costs 25 946 — — — 946 Interest capitalised (c) 8 — — — 340 340 Additions 329 45 726 5,211 6,311 Depreciation for the year (a)(d) (666) (354) (2,776) — (3,796) Impairment charges (e) (327) (85) (369) (82) (863) Disposals (2) (13) (64) (16) (95) Transfers and other movements (f) 34 66 1,988 (2,119) (31) At 31 December 2020 11,173 6,369 32,754 11,711 62,007 – cost 25,052 12,178 71,603 12,906 121,739 – accumulated depreciation and impairment (13,879) (5,809) (38,849) (1,195) (59,732) Non-current assets pledged as security (g) 1,712 494 5,065 6,974 14,245 Year ended 31 December 2019 Note Mining properties and leases (a) US$m Land and buildings US$m Plant Capital Total Net book value At 1 January 2019 11,063 6,263 32,019 7,016 56,361 Adjustment for transition to new accounting standard (h) — — (31) — (31) Restated opening balance 11,063 6,263 31,988 7,016 56,330 Adjustment on currency translation (b) 27 72 286 41 426 Adjustments to capitalised closure costs 25 840 — — — 840 Interest capitalised (c) 8 — — — 321 321 Additions 433 46 616 4,435 5,530 Depreciation for the year (a)(d) (729) (381) (2,869) — (3,979) Impairment charges (e) (1,339) (96) (1,115) (926) (3,476) Disposals — (9) (44) (19) (72) Transfers and other movements (f) 107 508 2,629 (2,857) 387 At 31 December 2019 10,402 6,403 31,491 8,011 56,307 – cost 24,875 11,517 66,705 9,188 112,285 – accumulated depreciation and impairment (14,473) (5,114) (35,214) (1,177) (55,978) Non-current assets pledged as security (g) 1,805 571 5,111 5,271 12,758 (a) At 31 December 2020, the net book value of capitalised production phase stripping costs totalled US$2,398 million, with US$2,019 million within "Property, plant and equipment" and a further US$379 million within "Investments in equity accounted units" (2019: total of US$2,276 million, with US$1,833 million in "Property, plant and equipment" and a further US$443 million within "Investments in equity accounted units"). During the year, capitalisation of US$380 million was partly offset by depreciation of US$267 million (including amounts recorded within equity accounted units). Depreciation of deferred stripping costs in respect of subsidiaries of US$145 million (2019: US$139 million; 2018: US$134 million) is included within “Depreciation for the year”. (b) Adjustment on currency translation represents the impact of exchange differences arising on the translation of the assets of entities with functional currencies other than the US dollar, recognised directly in the currency translation reserve. The adjustment in 2020 arose from the strengthening of the Australian dollar and Canadian dollar against the US dollar. (c) Interest is capitalised at a rate based on the Group or relevant subsidiary’s cost of borrowing or at the rate on project specific debt, where applicable. The Group’s average borrowing rate used for capitalisation of interest is 4.20% (2019: 5.30%). (d) Assets within operations for which production is not expected to fluctuate significantly from one year to another or which have a physical life shorter than the related mine are depreciated on a straight line basis as follows: Land and buildings: Land: not depreciated Buildings: five Plant and equipment: Other plant and equipment: three Power assets: 25 to 50 years Capital work in progress: not depreciated (e) During 2020, impairment charges relate to Pacific Aluminium smelters, the ISAL smelter in Iceland and our interest in the Diavik diamond mine (see note 6). During 2019, impairment charges primarily related to the Oyu Tolgoi underground project, Yarwun alumina refinery and the ISAL smelter (see note 6). (f) “Transfers and other movements” includes reclassifications between categories. In 2019, "Transfers and other movements" included ISAL assets held for sale as these assets no longer met the criteria to be classified as assets held for sale. (g) Excludes assets held under capitalised lease arrangements. Non-current assets pledged as security represent amounts pledged as collateral against US$4,518 million (2019: US$4,540 million) of loans, which are included in note 21.
Schedule of Property, Plant and Equipment, Right-of-Use Assets	Right-of-use assets – Leased Land Plant Total Net book value 31 December 2020 475 400 875 31 December 2019 507 558 1,065 Additions for the year 31 December 2020 30 75 105 31 December 2019 89 212 301 Depreciation for the year (included within operating costs) 31 December 2020 (93) (229) (322) 31 December 2019 (69) (203) (272) Impairment charges (a) 31 December 2020 (6) (31) (37) 31 December 2019 (6) (4) (10) (a) Impairment charges in 2020 relate to Pacific Aluminium smelters, the ISAL smelter in Iceland and our interest in the Diavik diamond mine (see note 6). Impairment charges in 2019 related to the ISAL smelter (see note 6).

Investments in equity account_2

Investments in equity accounted units (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Investments Accounted For Using Equity Method Explanatory [Abstract]
Summary of investments in equity accounted units	Summary balance sheet (Rio Tinto share) 2020 US$m 2019 US$m Rio Tinto's share of assets – Non-current assets 5,307 5,820 – Current assets 1,077 831 6,384 6,651 Rio Tinto's share of liabilities – Current liabilities (785) (675) – Non-current liabilities (1,835) (2,005) (2,620) (2,680) Rio Tinto's share of net assets 3,764 3,971

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Inventories [Abstract]
Summary of inventories	2020 US$m 2019 US$m Raw materials and purchased components 640 675 Consumable stores 1,050 925 Work in progress 1,288 1,066 Finished goods and goods for resale 1,113 936 Total inventories 4,091 3,602 Comprising: Expected to be used within one year 3,917 3,463 Expected to be used after more than one year 174 139 Total inventories 4,091 3,602

Deferred taxation (Tables)

Deferred taxation (Tables)	12 Months Ended
	Dec. 31, 2020
Deferred tax assets and liabilities [abstract]
Reconciliation of changes in deferred tax liability asset	2020 US$m 2019 US$m At 1 January – deferred tax liability (118) (532) Adjustment on currency translation (43) (77) Credited to the income statement 178 289 Credited to statement of comprehensive income (a) 115 77 Other movements (b) 14 125 At 31 December – deferred tax asset/(liability) 146 (118) Comprising: – deferred tax assets (c)(d) 3,385 3,102 – deferred tax liabilities (e) (3,239) (3,220)
Deferred tax liabilities and assets, prior to offsetting of balances	Analysis of deferred tax Total 2020 US$m Total 2019 US$m Deferred tax assets arising from: Tax losses (c) 1,867 1,847 Provisions 2,121 1,810 Capital allowances 529 604 Post-retirement benefits 698 599 Unrealised exchange losses 204 176 Other temporary differences 1,046 931 Total 6,465 5,967 Deferred tax liabilities arising from: Capital allowances (4,966) (4,742) Unremitted earnings (e) (402) (411) Capitalised interest (351) (387) Post-retirement benefits (224) (253) Unrealised exchange gains (7) (3) Other temporary differences (369) (289) Total (6,319) (6,085) Credited /(charged) to the income statement Unrealised exchange losses 25 (21) Tax losses 12 (164) Provisions 188 175 Capital allowances (82) 181 Tax on unremitted earnings 1 (5) Post-retirement benefits 9 (18) Other temporary differences 25 141 Total 178 289 (a) The amounts credited directly to the statement of comprehensive income include provisions for tax on exchange differences on intragroup loans qualifying for reporting as part of the net investment in subsidiaries, on cash flow hedges and on actuarial gains and losses on pension schemes and on post-retirement healthcare plans. (b) “Other movements” include deferred tax relating to tax payable recognised by subsidiary holding companies on the profits of the equity accounted units to which it relates. (c) There is a limited time period, the shortest of which is one year , for the recovery of US$1,617 million ( 2019 : US$1,186 million; six years ) of tax losses and other tax assets which have been recognised as deferred tax assets in the financial statements. (d) Recognised and unrecognised deferred tax assets are shown in the table below and totalled US$7,226 million at 31 December 2020 ( 2019 : US$6,264 million ). Of this total, US$3,385 million has been recognised as deferred tax assets ( 2019 : US$3,102 million ), leaving US$3,841 million ( 2019 : US$3,162 million ) unrecognised, as recovery is not considered probable. (e) Deferred tax liabilities are not recognised on the unremitted earnings of subsidiaries and joi nt ventures totalling US$2,895 million ( 2019 : US$3,861 million ) where the Group is able to control the timing of the remittance and it is probable that there will be no remittance in the foreseeable future. If these earnings were remitted, tax of US$112 million ( 2019 : US$164 million ) would be payable.
Recognised and unrecognised amounts in deferred tax assets	The recognised amounts in the table below do not include deferred tax assets that have been netted off against deferred tax liabilities. Analysis of deferred tax assets Recognised Unrecognised 2020 US$m 2019 US$m 2020 US$m 2019 US$m France — — 1,284 1,111 Canada 617 492 574 566 US 938 920 84 51 Australia 649 698 528 316 Mongolia (a) 974 704 540 721 Other 207 288 831 397 Total (b) 3,385 3,102 3,841 3,162 (a) Deferred tax assets in Mongolia include US$292 million (2019: US$130 million) from tax losses that expire if not recovered against taxable profits within eight years. Tax losses have been calculated in accordance with the tax stability provisions of the Oyu Tolgoi Investment Agreement and Mongolian laws. Recovery of the recognised deferred tax assets is expected to commence from 2021 based on projected cash flows, consistent with the latest life of mine plan described in note 6. The interpretation of the stabilised tax laws by the Mongolian Tax Authority has been, and is expected to continue to be, subject to dispute. Changes to agreements or their interpretation could have a material impact on the amount and period of recovery of deferred tax assets. (b) US$720 million (2019: US$695 million) of the unrecognised assets relate to realised or unrealised capital losses, the recovery of which depends on the existence of capital gains in future years. There are time limits, the shortest of which is one year, for the recovery of US$551 million of the unrecognised assets (2019: US$491 million).

Receivables and other assets (T

Receivables and other assets (Tables)	12 Months Ended
	Dec. 31, 2020
Trade and other receivables [abstract]
Disclosure Of Detailed Information About Trade And Other Receivables Explanatory	Non-current 2020 US$m Current 2020 US$m Total 2020 US$m Non-current 2019 US$m Current 2019 US$m Total 2019 US$m Trade receivables (a) 1 2,543 2,544 1 2,097 2,098 Other financial receivables (a) 339 332 671 286 453 739 Receivables relating to net investment in finance leases (a) 29 9 38 52 11 63 Amounts due from equity accounted units (a) — 33 33 — 38 38 Other receivables (b) 369 422 791 123 209 332 Prepayment of tolling charges to jointly controlled entities (c) 218 — 218 221 — 221 Pension surpluses (note 42) 782 — 782 984 — 984 Other prepayments 58 305 363 49 219 268 Total 1,796 3,644 5,440 1,716 3,027 4,743 (a) At 31 December 2020, trade and other financial receivables, receivables relating to net investment in finance leases and amounts due from equity accounted units are stated net of allowances for expected credit losses of US$59 million (20 19: US$54 million). (b) At 31 December 2020, other non-current receivables included US$315 million (2019: US$53 million) and other current receivables US$95 million (2019: US$nil) related to Energy Resources of Australia Ltd (ERA's) deposit held in a trust fund which is controlled by the Government of Australia. During 2020, ERA deposited US$299 million into the trust fund which is recorded in "Other investing cash flows" in the Group cash flow statement. ERA are entitled to reimbursement from the fund once specific phases of rehabilitation relating to the Ranger Project are completed. The fund is outside of the scope of IFRS 9 - "Financial Instruments" and therefore classified as an "other receivable" within "Receivables and other assets".

Other financial assets (Tables)

Other financial assets (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Other Financial Assets [Abstract]
Summary of other financial assets including non-quasi equity loans to equity accounted units	Non-current 2020 US$m Current 2020 US$m Total 2020 US$m Non-current 2019 US$m Current 2019 US$m Total 2019 US$m Derivative financial instruments 531 134 665 308 58 366 Equity shares and quoted funds 66 9 75 52 9 61 Other investments, including loans (a) 231 2,668 2,899 236 2,603 2,839 Loans to equity accounted units 1 40 41 39 — 39 Total 829 2,851 3,680 635 2,670 3,305 (a) Current “Other investments, including loans” includes US$2,538 million (2019: US$2,584 million) of highly liquid financial assets held in managed investment funds classified as held for trading.

Cash and cash equivalents (Tabl

Cash and cash equivalents (Tables)	12 Months Ended
	Dec. 31, 2020
Cash and cash equivalents [abstract]
Summary of cash and cash equivalents	2020 US$m 2019 US$m Cash at bank and in hand 1,150 978 Money market funds, reverse repurchase agreements and other cash equivalents (a) 9,231 7,049 Balance per Group balance sheet and Group cash flow statement 10,381 8,027 (a) We continue to diversify the financial products we invest our surplus cash in. During the year, we purchased securities under resale agreements ("reverse repurchase agreements”). At 31 December 2020 we held US$1,200 million of reverse repurchase agreements, measured at amortised cost and reported within cash and cash equivalents as they are highly liquid products maturing within three months. We accepted collateral of investment grade quality in respect of these reverse repurchase agreements, with a fair value of US$1,260 million as at 31 December 2020. Collateral is not recognised on our balance sheet and in the event of counterparty's default we would be able to sell it.

Borrowings and other financia_2

Borrowings and other financial liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Borrowings And Other Financial Liabilities [Abstract]
Summary of borrowings	Note Non-current 2020 US$m Current 2020 US$m Total 2020 US$m Non-current 2019 US$m Current 2019 US$m Total 2019 US$m Rio Tinto Finance plc Euro Bonds 2.0% due 2020 (a)(b)(c) — — — — 455 455 Rio Tinto Finance plc Euro Bonds 2.875% due 2024 (a)(b) 555 — 555 508 — 508 Rio Tinto Finance (USA) Limited Bonds 3.75% 2025 (a) 1,299 — 1,299 1,229 — 1,229 Rio Tinto Finance (USA) Limited Bonds 7.125% 2028 (a) 1,005 — 1,005 958 — 958 Alcan Inc. Debentures 7.25% due 2028 (a) 109 — 109 104 — 104 Rio Tinto Finance plc Sterling Bonds 4.0% due 2029 (a)(b) 717 — 717 647 — 647 Alcan Inc. Debentures 7.25% due 2031 (d) 438 — 438 419 — 419 Alcan Inc. Global Notes 6.125% due 2033 (d) 744 — 744 742 — 742 Alcan Inc. Global Notes 5.75% due 2035 (d) 292 — 292 289 — 289 Rio Tinto Finance (USA) Limited Bonds 5.2% 2040 (a) 1,173 — 1,173 1,137 — 1,137 Rio Tinto Finance (USA) plc Bonds 4.75% 2042 (a) 501 — 501 483 — 483 Rio Tinto Finance (USA) plc Bonds 4.125% 2042 (a) 743 — 743 716 — 716 Oyu Tolgoi LLC MIGA Insured Loan LIBOR plus 2.65% due 2027 (e) 674 4 678 676 3 679 Oyu Tolgoi LLC Commercial Banks "B Loan" LIBOR plus 3.4% due 2027 (e) 1,571 10 1,581 1,581 8 1,589 Oyu Tolgoi LLC Export Credit Agencies Loan 2.3% due 2028 (e) 275 2 277 273 3 276 Oyu Tolgoi LLC Export Credit Agencies Loan LIBOR plus 3.65% due 2029 (e) 867 5 872 869 5 874 Oyu Tolgoi LLC International Financial Institutions "A Loan" LIBOR plus 3.78% due 2030 (e) 771 6 777 771 4 775 Other secured loans 246 68 314 302 45 347 Other unsecured loans 322 256 578 382 197 579 Lease liabilities 22 945 233 1,178 1,007 302 1,309 Total borrowings including overdrafts (f) 13,247 584 13,831 13,093 1,022 14,115 (a) These borrowings are subject to hedging arrangements and are summarised in the interest rate risk section of note 29. (b) Rio Tinto has a US$10 billion (2019: US$10 billion) European Debt Issuance Programme against which the cumulative amount utilised was US$1.2 billion equivalent at 31 December 2020 (2019: US$1.6 billion). The carrying value of these bonds after hedge accounting adjustments amounted to US$1.3 billion (2019: US$1.6 billion) in aggregate. (c) On 11 May 2020, we repaid our €402 million (nominal value) Rio Tinto Finance plc Euro Bonds on their maturity. The cash outflow relating to the repayment of the bonds and the realised loss on the derivatives have been recognised within "Repayment of borrowings and associated derivatives" in the Group cash flow statement and totalled US$526 million. (d) In 2020 we entered into new swaps to convert the interest payable in relation to these bonds from fixed to floating rates. Refer to Note 29 for more details. (e) These borrowings relate to the Oyu Tolgoi LLC project finance facility. The project finance facility provides for interest-only payments for the first five years from 2016 followed by minimum repayments according to a stepped amortisation schedule for the remaining life of the facility. The due dates stated represent the final repayment date. The interest rates stated are pre-completion and will increase by 1% post-completion. (f) The Group’s borrowings of US$13.8 billion (2019: US$14.1 billion) include US$4.5 billion (2019: US$4.5 billion) of subsidiary entity borrowings that are subject to various financial and general covenants with which the respective borrowers were in compliance as at 31 December 2020 .
Summary of borrowings and other financial liabilities	Other financial liabilities Non-current 2020 US$m Current 2020 US$m Total 2020 US$m Non-current 2019 US$m Current 2019 US$m Total 2019 US$m Derivative financial instruments 161 23 184 248 103 351 Other financial liabilities (a) — — — — 247 247 Total other financial liabilities 161 23 184 248 350 598 Total borrowings including overdrafts (as above) 13,247 584 13,831 13,093 1,022 14,115 Total borrowings and other financial liabilities 13,408 607 14,015 13,341 1,372 14,713 (a) At 31 December 2019, other financial liabilities included US$207 million in relation to the share buy-back programme, which was completed in February 2020.

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of leases [Abstract]
Disclosure of additional information about leasing activities for lessee	We have made the following payments associated with leases: Description of payment 2020 2019 Included within Principal lease payments 324 315 Cash flows from financing activities Interest payments on leases 50 53 Cash flows from operating activities Payments for short-term leases 314 327 Net operating costs Payments for variable lease components 30 15 Net operating costs Payments for low value leases (>12 months in duration) 1 1 Net operating costs Total lease payments 719 711
Summary of capitalised finance leases	The maturity profile of lease liabilities recognised at the balance sheet date is: Note 2020 US$m 2019 US$m Lease liabilities Due within 1 year 271 349 Between 1 and 3 years 386 424 Between 3 and 5 years 185 226 More than 5 years 724 671 Total undiscounted cash payments expected to be made 1,566 1,670 Effect of discounting (388) (361) Present value of minimum lease payments 21 1,178 1,309

Consolidated net cash_(debt) (T

Consolidated net cash/(debt) (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Consolidated Net Debt [Abstract]
Analysis of changes in consolidated net cash/(debt)	Financing liabilities Other assets Year ended 31 December 2020 Borrowings excluding overdrafts (a) US$m Lease liabilities (b) US$m Debt-related derivatives (included in Other financial assets/liabilities) (c) US$m Cash and cash equivalents (d) US$m Other investments (e) US$m Net Analysis of changes in consolidated net debt Opening balance (12,806) (1,309) (147) 8,027 2,584 (3,651) Foreign exchange adjustment (83) (47) 39 165 — 74 Cash movements excluding exchange movements 505 324 91 2,189 (58) 3,051 Other non-cash movements (269) (146) 265 — 12 (138) Closing balance (12,653) (1,178) 248 10,381 2,538 (664) Year ended 31 December 2019 Financing liabilities Other assets Borrowings excluding overdrafts (a) US$m Lease liabilities (b) US$m Debt-related derivatives (included in Other financial assets/ liabilities) (c) US$m Cash and cash equivalents (d) US$m Other investments (e) US$m Net Analysis of changes in consolidated net (debt)/cash Opening balance (12,707) (44) (288) 10,772 2,522 255 Adjustment for transition to new accounting standard (f) — (1,248) — — — (1,248) Foreign exchange adjustment (5) (9) 3 (54) — (65) Cash movements excluding exchange movements 123 315 — (2,808) 28 (2,342) Other non-cash movements (217) (323) 138 117 34 (251) Closing balance (12,806) (1,309) (147) 8,027 2,584 (3,651) (a) Borrowings excluding overdrafts and including lease liabilities at 31 December 2020 of US$13,831 million (2019: US$14,115 million) differ from total borrowings and other financial liabilities of US$14,015 million (2019: US$14,713 million) on the balance sheet as they exclude other current financial liabilities of US$23 million (2019: US$350 million) and other non-current financial liabilities of US$161 million (2019: US$248 million). (b) Other movements in lease liabilities include the net impact of additions, modifications and terminations during the year. (c) Included within "Debt-related derivatives" are interest rate and cross currency interest rate swaps that are in hedge relationships with the Group's debt. (d) Other non-cash movements in the year ended 31 December 2019 of US$117 million represents the elimination of cash movements during the year in respect of assets held for sale which are included in the cash flow statement. (e) Other investments comprise US$2,538 million (2019: US$2,584 million) of highly liquid financial assets held in managed investment funds classified as held for trading. (f) The impact of the transition to new accounting pronouncement IFRS 16 “Leases” on 1 January 2019.

Trade and other payables (Table

Trade and other payables (Tables)	12 Months Ended
	Dec. 31, 2020
Trade and other payables [abstract]
Summary of trade and other payables	Non-current 2020 US$m Current 2020 US$m Total 2020 US$m Non-current 2019 US$m Current 2019 US$m Total 2019 US$m Trade payables 1 3,124 3,125 — 2,855 2,855 Other financial payables 298 862 1,160 272 668 940 Other payables 97 115 212 110 97 207 Deferred income (a) 133 344 477 143 200 343 Accruals 27 1,294 1,321 27 1,305 1,332 Employee entitlements — 762 762 — 650 650 Royalties and mining taxes 3 863 866 4 596 600 Amounts owed to equity accounted units 190 51 241 167 104 271 Government grants deferred 71 6 77 71 5 76 Total 820 7,421 8,241 794 6,480 7,274 (a) Deferred income includes contract liabilities of US$338 million ( 2019 : US$158 million ).

Provisions (including post-re_2

Provisions (including post-retirement benefits) (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of other provisions [abstract]
Summary of Provisions including post-retirement benefits	Note Pensions and post-retirement healthcare (a) US$m Other employee entitlements (b) US$m Close-down and restoration/ environmental (c) US$m Other Total 2020 US$m Total 2019 US$m At 1 January 2,714 354 11,090 945 15,103 13,608 Adjustment to opening balance on transition to new accounting standard (d) — — — — — (66) Restated opening balance 2,714 354 11,090 945 15,103 13,542 Adjustment on currency translation 83 34 736 37 890 65 Adjustments to mining properties/right of use assets: 14 – increases to existing and new provisions — — 130 11 141 840 – change in discount rate — — 816 — 816 — Charged/(credited) to profit: – increases to existing and new provisions 200 127 562 185 1,074 850 – change in discount rate — — 138 2 140 — – unused amounts reversed — (19) (123) (157) (299) (100) – exchange losses on provisions — — (21) (1) (22) 3 – amortisation of discount — — 373 4 377 387 Utilised in year (192) (77) (366) (139) (774) (744) Actuarial losses recognised in equity 250 — — — 250 235 Transfers and other movements — — — (31) (31) 25 At 31 December 3,055 419 13,335 856 17,665 15,103 Balance sheet analysis: Current 70 327 777 555 1,729 1,399 Non-current 2,985 92 12,558 301 15,936 13,704 Total 3,055 419 13,335 856 17,665 15,103 Projected cash spend for the undiscounted close-down and restoration/environmental clean up provision Undiscounted close-down and environmental restoration cash flows <1yr 1-3 yrs 3-5 yrs > 5 yrs Total US$m At 31 December 2020 776 1,203 1,433 13,988 17,400 At 31 December 2019 541 955 1,100 13,470 16,066 (a) The main assumptions used to determine the provision for pensions and post-retirement healthcare, and other information, including the expected level of future funding payments in respect of those arrangements, are given in note 42. (b) The provision for other employee entitlements includes a provision for long service leave of US$283 million ( 2019: US$248 million), based on the relevant entitlements in certain Group operations and includes US$62 million (2019: US$30 million) of provision for redundancy and severance payments. (c) The Group’s policy on close-down and restoration costs is described in note 1(l) and in paragraph (iii) under “Critical accounting policies and estimates” on page 219. Close-down and restoration costs are a normal consequence of mining, and the majority of close-down and restoration expenditure is incurred in the years following closure of the mine, refinery or smelter. Non-current provisions for close-down and restoration/environmental expenditure include amounts relating to environmental clean-up of US$468 million ( 2019: US$382 million) expected to take place between one and five years from the balance sheet date, and US$937 million (2019: US$883 million) expected to take place later than five years after the balance sheet date. Close-down and restoration/environmental liabilities at 31 December 2020 have not been adjusted for closure related receivables amounting to US$574 million (31 December 2019: US$166 million) due from the ERA trust fund, the co-owners of the Diavik Joint Venture and other financial assets held for the purposes of meeting closure obligations. (d) Impact of the transition to new accounting pronouncement IFRS 16 “Leases” on 1 January 2019.
Schedule of Cash Spend for Undiscounted Close-Down and Environmental Restoration Obligation	Projected cash spend for the undiscounted close-down and restoration/environmental clean up provision Undiscounted close-down and environmental restoration cash flows <1yr 1-3 yrs 3-5 yrs > 5 yrs Total US$m At 31 December 2020 776 1,203 1,433 13,988 17,400 At 31 December 2019 541 955 1,100 13,470 16,066
Schedule of Close-Down, Restoration and Environmental Provisions	Analysis of close-down and restoration/environmental clean up provisions As at 31 December Undiscounted close-down and environmental restoration obligations 17,400 16,066 Impact of discounting (4,065) (4,976) Present closure obligation 13,335 11,090 Attributable to: Operating sites 10,736 9,255 Non-operating sites 2,599 1,835 Total 13,335 11,090 Closure cost composition as at 31 December Decommissioning, decontamination and demolition 3,131 2,066 Closure and rehabilitation earthworks (a) 4,223 3,889 Long-term water management costs (b) 966 920 Post closure monitoring and maintenance 1,318 855 Indirect costs, owners' costs and contingency (c) 3,697 3,360 Total 13,335 11,090 The underlying costs for closure have been estimated with varying degrees of accuracy based on a function of the age of the underlying asset and proximity to closure. For assets within ten years of closure, closure plans and cost estimates are supported by detailed studies which are refined as the closure date approaches. These closure studies consider climate change and plan for resilience to expected climate conditions with a particular focus on precipitation rates. For new developments, consideration of climate change and ultimate closure conditions are an important part of the approval process. For longer-lived assets, closure provisions are typically based on conceptual level studies that are refreshed at least every five years; these are evolving to incorporate greater consideration of forecast climate conditions at closure. (a) A key component of earthworks rehabilitation involves re-landscaping the area disturbed by mining activities utilising the largely diesel powered heavy mobile equipment. In developing low-carbon solutions for our mobile fleet, this may include electrification of the vehicles during the mine life. The forecast cash flows for the heavy mobile equipment in the closure cost estimate are based on existing fuel sources; these could reduce if this power is sourced from renewable energy. (b) Long-term water management relates to the post-closure treatment of water due to acid rock drainage and other environmental commitments and is an area of research and development focus for our Closure team. The cost of this water processing can continue for many years after the bulk earthworks and demolition activities have completed and are therefore exposed to long-term climate change. This could materially affect rates of precipitation and therefore change the volume of water requiring processing. It is not currently possible to forecast accurately the impact this could have on the closure provision as some of our locations could experience drier conditions whereas others could experience greater rainfall. A further consideration relates to the alternative commercial use for the processed water which could support ultimate transfer of these costs to a third party. (c) Indirect costs, owners' costs and contingency include adjustments to the underlying cash flows to align the closure provision with a central-case estimate. This excludes allowances for quantitative estimation uncertainties which are allocated to the underlying cost driver and presented within the respective cost categories above. Geographic composition as at 31 December Australia 7,076 5,610 USA 3,819 3,377 Canada 1,482 1,267 Rest of World 958 836 Total 13,335 11,090

Share capital - Rio Tinto plc (

Share capital - Rio Tinto plc (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of classes of share capital [abstract]
Summary of share capital rio tinto plc	2020 Number (million) 2019 Number (million) 2018 Number (million) 2020 US$m 2019 US$m 2018 US$m Issued and fully paid up share capital of 10p each At 1 January 1,259.345 1,287.660 1,351.609 207 211 220 Ordinary shares issued (a)(c) 0.039 0.041 0.035 — — — Shares purchased and cancelled (b) (3.628) (28.356) (63.984) — (4) (9) At 31 December 1,255.756 1,259.345 1,287.660 207 207 211 Shares held by public At 1 January 1,249.924 1,278.215 1,342.058 Shares reissued from treasury (a) 0.569 0.024 0.106 Ordinary shares issued (a)(c) 0.039 0.041 0.035 Shares purchased and cancelled (b) (3.628) (28.356) (63.984) At 31 December 1,246.904 1,249.924 1,278.215 Shares held in treasury 8.852 9.421 9.445 Shares held by public 1,246.904 1,249.924 1,278.215 Total share capital 1,255.756 1,259.345 1,287.660 Other share classes Special Voting Share of 10p each (d) 1 only 1 only 1 only DLC Dividend Share of 10p each (d) 1 only 1 only 1 only Equalisation Share of 10p each (d) 1 only 1 only 1 only (a) 39,273 ordinary shares were issued in 2020 under the Global Employee Share Plan (GESP). 568,863 ordinary shares were reissued from treasury during the year resulting from the vesting of awards under Rio Tinto plc employee share-based payment plans, with market values between £32.74 and £56.32 per share (2019: 40,974 ordinary shares were issued under the GESP and 23,659 ordinary shares were reissued from treasury with exercise prices and market values between £36.33 and £49.74 per share; 2018: 35,380 ordinary shares were issued under the GESP and 106,045 ordinary shares reissued from treasury with exercise prices and market values between £16.53 and £43.79 per share). (b) The authority for the company to buy back its ordinary shares was renewed at the 2020 annual general meeting. 3,627,568 shares were bought back and cancelled in 2020 under the on-market buy-back programme. 28,356,034 shares were bought back and cancelled in 2019 under the on-market buy-back programme. 63,984,287 shares were bought back in 2018 under the on-market buy-back programme. (c) The aggregate consideration for new shares issued under the GESP was US$1.3 million (2019: US$1.1 million; 2018: US$1.0 million). The difference between the nominal value and the issue price of the shares issued was credited to the share premium account. The aggregate consideration received for treasury shares reissued was US$1 million (2019: US$1 million; 2018: US$6 million). No new shares were issued as a result of the exercise of options under Rio Tinto plc employee share-based payment plans in 2020, 2019 and 2018.

Share capital - Rio Tinto Lim_2

Share capital - Rio Tinto Limited (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of classes of share capital [abstract]
Summary of share capital rio tinto limited	2020 Number (million) 2019 Number (million) 2018 Number (million) 2020 US$m 2019 US$m 2018 US$m Issued and fully paid up share capital At 1 January 371.21 371.21 412.41 3,448 3,477 4,140 Adjustment on currency translation 333 (29) (382) Ordinary shares purchased and cancelled (a) — — (41.20) — — (281) At 31 December 371.21 371.21 371.21 3,781 3,448 3,477 – Special Voting Share (b) 1 only 1 only 1 only – DLC Dividend Share (c) 1 only 1 only 1 only Total share capital 371.21 371.21 371.21 (a) In November 2018, 41,198,134 Rio Tinto Limited ordinary shares were purchased at A$69.69 per share and cancelled under an off-market share buy-back programme carried out pursuant to the shareholder approval granted at Rio Tinto Limited’s 2018 annual general meeting for off-market and on-market buy-backs of up to 41.2 million Rio Tinto Limited ordinary shares.

Other reserves and retained e_2

Other reserves and retained earnings (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Other Reserves And Retained Earnings [Abstract]
Summary of other reserves and retained earnings	2020 US$m 2019 US$m 2018 US$m Capital redemption reserve (a) At 1 January 51 47 38 Own shares purchased and cancelled — 4 9 At 31 December 51 51 47 Cash flow hedge reserve At 1 January 160 195 32 Adjustment for transition to new accounting pronouncements (b) — — (4) Cash flow hedge gains 24 12 156 Cash flow hedge (gains)/losses transferred to the income statement (63) (41) 40 Tax on the above 3 (6) (54) Transfers and other movements — — 25 At 31 December 124 160 195 Available for sale revaluation reserves At 1 January — — 20 Adjustment for transition to new accounting pronouncements (b) — — (20) Gains on available for sale securities — — — Losses on available for sale securities transferred to the income statement — — — Tax on the above — — — Transfers and other movements — — — At 31 December — — — Fair value through other comprehensive income reserve At 1 January (11) (6) — Adjustment for transition to new accounting pronouncements (b) — — 8 Losses on equity investments 9 (5) (11) Transfers to retained earnings — — (3) At 31 December (2) (11) (6) Cost of hedging reserve At 1 January (10) (13) — Adjustment for transition to new accounting pronouncements (b) — — 26 Cost of hedging deferred to reserves during the year 7 3 (36) Transfer of cost of hedging to the income statement — — (3) At 31 December (3) (10) (13) Other reserves (c) At 1 January 11,643 11,650 11,714 Own shares purchased from Rio Tinto Limited shareholders to satisfy share options (76) (63) (114) Employee share options: value of services 60 52 52 Deferred tax on share options 1 4 (2) At 31 December 11,628 11,643 11,650 Foreign currency translation reserve (d) At 1 January (2,656) (3,212) 480 Parent and subsidiaries' currency translation and exchange adjustments 2,814 331 (3,658) Equity accounted units currency translation adjustments 4 10 (48) Currency translation reclassified on disposal — 215 14 At 31 December 162 (2,656) (3,212) Total other reserves per balance sheet 11,960 9,177 8,661 28 Other reserves and retained earnings continued 2020 US$m 2019 US$m 2018 US$m Retained earnings (e) At 1 January 23,387 27,025 23,761 Adjustment for transition to new accounting pronouncements (b) — (113) (179) Parent and subsidiaries' profit for the year 9,456 7,709 13,125 Equity accounted units' profit after tax for the year 313 301 513 Actuarial (losses)/gains (f) (482) (259) 894 Tax relating to components of other comprehensive income 116 81 (269) Total comprehensive income for the year 9,403 7,832 14,263 Share buy-back programme (1) (1,135) (5,423) Dividends paid (6,132) (10,334) (5,356) Change in equity interest held by Rio Tinto 84 85 60 Own shares purchased/treasury shares reissued for share options and other movements (31) (43) (140) Employee share options and other IFRS 2 charges taken to the income statement 82 70 61 Transfer from FVOCI reserve — — 3 Transfers and other movements — — (25) At 31 December 26,792 23,387 27,025 (a) The capital redemption reserve was set up to comply with section 733 of the UK Companies Act 2006 (previously section 170 of the UK Companies Act 1985) when shares of a company are redeemed or purchased wholly out of the company’s profits. Balances reflect the amount by which the company’s issued share capital is diminished in accordance with this section. (b) The impact of the transition to new accounting pronouncements; IFRS 16 “Leases” and IFRIC 23 "Uncertainty over income tax treatments" on 1 January 2019 and IFRS 9 “Financial Instruments” and IFRS 15 "Revenue from Contracts with Customers" on 1 January 2018. (c) Other reserves includes US$11,936 million which represents the difference between the nominal value and issue price of the shares issued arising from Rio Tinto plc’s rights issue completed in July 2009. No share premium was recorded in the Rio Tinto plc financial statements through the operation of the merger relief provisions of the UK Companies Act 1985. Other reserves also include the cumulative amount recognised under IFRS 2 in respect of options granted but not exercised to acquire shares in Rio Tinto Limited, less, where applicable, the cost of shares purchased to satisfy share options exercised. The cumulative amount recognised under IFRS 2 in respect of options granted but not exercised to acquire shares in Rio Tinto plc is recorded in retained earnings. (d) Exchange differences arising on the translation of the Group’s net investment in foreign controlled companies are taken to the foreign currency translation reserve, as described in note 1(d). The cumulative differences relating to an investment are transferred to the income statement when the investment is disposed of. (e) Retained earnings and movements in reserves of subsidiaries include those arising from the Group’s share of joint operations.

Financial instruments and ris_2

Financial instruments and risk management (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of detailed information about financial instruments [abstract]
Summary of financial assets by categories	A (a) Financial assets and liabilities by categories At 31 December 2020 Note Total Amortised Fair value through other Fair value Financial assets Cash and cash equivalents 20 10,381 3,970 — 6,411 Trade and other financial receivables (a)(b) 18 3,286 1,479 — 1,807 Equity shares and quoted funds 19 75 — 64 11 Other investments, including loans (c) 19 2,899 138 — 2,761 Derivatives related to net debt: designated as hedges (d) 19, 23 388 — — 388 Derivatives and embedded derivatives not related to net debt: not designated as hedges (d) 19 204 — — 204 Embedded derivatives not related to net debt: designated as hedges (d) 19 73 — — 73 Loans to equity accounted units including quasi equity loans 153 153 — — Total financial assets 17,459 5,740 64 11,655 Financial liabilities Trade and other financial payables (e) 24 (5,847) (5,817) (30) Short-term borrowings and bank overdrafts 21 (584) (584) — Medium-term and long-term borrowings 21 (13,247) (13,247) — Derivatives related to net debt: designated as hedges (d) 21, 23 (140) — (140) Derivatives and embedded derivatives not related to net debt: not designated as hedges (d) 21 (24) — (24) Embedded derivatives not related to net debt: designated as hedges (d) 21 (20) — (20) Other financial liabilities 21 — — — Total financial liabilities (19,862) (19,648) (214) At 31 December 2019 Note Total Amortised Fair value Fair value Financial assets Cash and cash equivalents 20 8,027 2,707 — 5,320 Trade and other financial receivables (a)(b) 18 2,938 1,801 — 1,137 Equity shares and quoted funds 19 61 — 50 11 Other investments, including loans (c) 19 2,839 21 — 2,818 Derivatives related to net debt: designated as hedges (d) 19, 23 151 — — 151 Derivatives and embedded derivatives not related to net debt: not designated as hedges (d) 19 149 — — 149 Embedded derivatives not related to net debt: designated as hedges (d) 19 66 — — 66 Loans to equity accounted units including quasi equity loans 152 152 — — Total financial assets 14,383 4,681 50 9,652 Financial liabilities Trade and other financial payables (e) 24 (5,398) (5,341) (57) Short-term borrowings and bank overdrafts 21 (1,022) (1,022) — Medium-term and long-term borrowings 21 (13,093) (13,093) — Derivatives related to net debt: designated as hedges (d) 21, 23 (298) — (298) Derivatives and embedded derivatives not related to net debt: not designated as hedges (d) 21 (29) — (29) Embedded derivatives not related to net debt: designated as hedges (d) 21 (24) — (24) Other financial liabilities 21 (247) (247) — Total financial liabilities (20,111) (19,703) (408) (a) Trade and other financial receivables comprise trade receivables, other financial receivables, receivables relating to net investments in finance leases and amounts due from equity accounted units within note 18. (b) Provisionally priced receivables are fair valued. (c) Other investments, including loans, includ e US$2,538 million ( 2019: US$2,584 million) of highly liquid financial assets in managed investment funds classified as held for trading. (d) These financial assets and liabilities in aggregate agree to the total derivative financial instruments disclosed in notes 19 and 21. (e) Trade and other financial payables comprise trade payables, other financial payables, accruals and amounts due to equity accounted units within note 24 . The trade and other payables held at fair value are valued using Level 2 inputs.
Summary of financial liabilities by categories	A (a) Financial assets and liabilities by categories At 31 December 2020 Note Total Amortised Fair value through other Fair value Financial assets Cash and cash equivalents 20 10,381 3,970 — 6,411 Trade and other financial receivables (a)(b) 18 3,286 1,479 — 1,807 Equity shares and quoted funds 19 75 — 64 11 Other investments, including loans (c) 19 2,899 138 — 2,761 Derivatives related to net debt: designated as hedges (d) 19, 23 388 — — 388 Derivatives and embedded derivatives not related to net debt: not designated as hedges (d) 19 204 — — 204 Embedded derivatives not related to net debt: designated as hedges (d) 19 73 — — 73 Loans to equity accounted units including quasi equity loans 153 153 — — Total financial assets 17,459 5,740 64 11,655 Financial liabilities Trade and other financial payables (e) 24 (5,847) (5,817) (30) Short-term borrowings and bank overdrafts 21 (584) (584) — Medium-term and long-term borrowings 21 (13,247) (13,247) — Derivatives related to net debt: designated as hedges (d) 21, 23 (140) — (140) Derivatives and embedded derivatives not related to net debt: not designated as hedges (d) 21 (24) — (24) Embedded derivatives not related to net debt: designated as hedges (d) 21 (20) — (20) Other financial liabilities 21 — — — Total financial liabilities (19,862) (19,648) (214) At 31 December 2019 Note Total Amortised Fair value Fair value Financial assets Cash and cash equivalents 20 8,027 2,707 — 5,320 Trade and other financial receivables (a)(b) 18 2,938 1,801 — 1,137 Equity shares and quoted funds 19 61 — 50 11 Other investments, including loans (c) 19 2,839 21 — 2,818 Derivatives related to net debt: designated as hedges (d) 19, 23 151 — — 151 Derivatives and embedded derivatives not related to net debt: not designated as hedges (d) 19 149 — — 149 Embedded derivatives not related to net debt: designated as hedges (d) 19 66 — — 66 Loans to equity accounted units including quasi equity loans 152 152 — — Total financial assets 14,383 4,681 50 9,652 Financial liabilities Trade and other financial payables (e) 24 (5,398) (5,341) (57) Short-term borrowings and bank overdrafts 21 (1,022) (1,022) — Medium-term and long-term borrowings 21 (13,093) (13,093) — Derivatives related to net debt: designated as hedges (d) 21, 23 (298) — (298) Derivatives and embedded derivatives not related to net debt: not designated as hedges (d) 21 (29) — (29) Embedded derivatives not related to net debt: designated as hedges (d) 21 (24) — (24) Other financial liabilities 21 (247) (247) — Total financial liabilities (20,111) (19,703) (408) (a) Trade and other financial receivables comprise trade receivables, other financial receivables, receivables relating to net investments in finance leases and amounts due from equity accounted units within note 18. (b) Provisionally priced receivables are fair valued. (c) Other investments, including loans, includ e US$2,538 million ( 2019: US$2,584 million) of highly liquid financial assets in managed investment funds classified as held for trading. (d) These financial assets and liabilities in aggregate agree to the total derivative financial instruments disclosed in notes 19 and 21. (e) Trade and other financial payables comprise trade payables, other financial payables, accruals and amounts due to equity accounted units within note 24 . The trade and other payables held at fair value are valued using Level 2 inputs.
Disclosure of issued capital	Our total capital as at 31 December was: Total capital Note 2020 US$m 2019 US$m Equity attributable to owners of Rio Tinto (see Group balance sheet) 47,054 40,532 Equity attributable to non-controlling interests (see Group balance sheet) 4,849 4,710 Net debt 23 664 3,651 Total capital 52,567 48,893
Summary of credit ratings	Our credit ratings, as provided by Standard & Poor’s and Moody’s investor services, as at 31 December were: 2020 2019 Long-term rating A/A2 A/A2 Short-term rating A-1/P-1 A-1/P-1 Outlook Stable/Stable Stable/Stable
Summary of notional aluminium forward sales contracts embedded in power contracts	In the table below, we summarise the maturity profile of our financial liabilities based on contractual undiscounted payments, which will therefore not necessarily agree with the amounts disclosed in the balance sheet. Financial liability analysis At 31 December 2020 (Outflows)/Inflows Within 1 Between Between Between Between After Total Non-derivative financial liabilities Trade and other financial payables (a) (5,251) (53) (15) (34) (19) (394) (5,766) Expected lease liability payments (271) (231) (155) (101) (84) (724) (1,566) Borrowings before swaps (351) (667) (743) (1,256) (1,892) (7,477) (12,386) Expected future interest payments (a) (525) (522) (495) (469) (427) (2,999) (5,437) Derivative financial liabilities (b) Derivatives related to net debt – net settled — — — — — — — Derivatives related to net debt – gross settled (a) : – gross inflows 27 27 27 27 27 790 925 – gross outflows (34) (34) (34) (34) (34) (943) (1,113) Derivatives not related to net debt – net settled (20) (7) (2) (2) (2) (9) (42) Derivatives not related to net debt – gross settled: – gross inflows 290 — — — — — 290 – gross outflows (291) — — — — — (291) Total (6,426) (1,487) (1,417) (1,869) (2,431) (11,756) (25,386) At 31 December 2019 Within 1 Between Between Between Between After Total Non-derivative financial liabilities Trade and other financial payables (a) (4,841) (45) (12) (14) (15) (380) (5,307) Expected lease liability payments (349) (267) (157) (133) (93) (671) (1,670) Borrowings before swaps (723) (171) (665) (741) (1,209) (9,320) (12,829) Expected future interest payments (a) (607) (594) (590) (551) (514) (3,518) (6,374) Other financial liabilities (247) — — — — — (247) Derivative financial liabilities (b) Derivatives related to net debt – net settled (16) (16) (16) 9 (3) 3 (39) Derivatives related to net debt – gross settled (a) : – gross inflows 495 40 40 40 507 788 1,910 – gross outflows (588) (53) (53) (53) (599) (977) (2,323) Derivatives not related to net debt – net settled (31) — — (2) (4) (23) (60) Derivatives not related to net debt – gross settled: – gross inflows 699 — — — — — 699 – gross outflows (703) — — — — — (703) Total (6,911) (1,106) (1,453) (1,445) (1,930) (14,098) (26,943) (a) The interest payable at year end was removed from trade and other financial payables and is shown within expected future interest payments. Interest payments have been projected using interest rates applicable at the end of the applicable financial year. Where debt is subject to variable interest rates, future interest payments are subject to change in line with market rates.
Summary of derivative financial instruments	We held the following notional aluminium forward sales contracts embedded in the power contracts: At 31 December 2020 Total Within 1 year Between 1 and 5 years Between 5 and 10 years After 10 years Notional amount (in tonnes) 640,963 72,548 287,587 280,828 — Notional amount (in US$ millions) 1,522 159 663 701 — Average hedged rate (in US$ per tonne) 2,375 2,189 2,305 2,495 — At 31 December 2019 Total Within 1 year Between 1 Between 5 After 10 years Notional amount (in tonnes) 704,370 65,226 286,617 352,527 — Notional amount (in US$ millions) 1,656 138 647 871 — Average hedged rate (in US$ per tonne) 2,351 2,114 2,257 2,471 — In the table below we summarise our derivatives, including embedded derivatives, as at 31 December. Total fair value 2020 2019 Asset Liability Asset Liability Derivatives designated as hedges Interest rate swaps (a) 386 (1) 151 (38) Cross-currency interest rate swaps (b) 2 (139) — (260) Aluminium embedded derivatives (c) 66 (20) 66 (24) Currency forward contracts 7 — — — Total derivatives designated as hedges 461 (160) 217 (322) Derivatives not designated as hedges Currency forward contracts and swaps 63 (1) 13 (5) Aluminium embedded derivatives (c) 80 — 96 — Other embedded derivatives 28 (16) 14 — Other commodity contracts (d) 33 (7) 26 (24) Total derivatives not designated as hedges 204 (24) 149 (29) Total derivative instruments 665 (184) 366 (351) Analysed by maturity: Less than 1 year 134 (23) 58 (103) Between 1 and 5 years 330 (14) 96 (86) More than 5 years 201 (147) 212 (162) Total 665 (184) 366 (351) Total net derivative instruments 481 15 Reconciliation to balance sheet 2020 US$m 2019 US$m Non-current assets 19 531 308 Current assets 19 134 58 Current liabilities 21 (23) (103) Non-current liabilities 21 (161) (248) Total net derivative instruments 481 15 (a) The interest rate swaps are used to convert certain fixed rate borrowings to a floating rate. (b) The cross-currency interest rate swaps are used to convert non-US dollar denominated borrowings to either fixed or floating US dollar borrowings. (c) Aluminium embedded derivatives (forward contracts and options) are contained within certain aluminium smelter electricity purchase contracts. These contracts reduce our margin exposure to movements in the aluminium price.
Summary of impact of hedging instrument on statement of financial position	The impact on our financial statements of these hedging instruments and hedging items are: Aluminium embedded derivatives separated from the power contract (Hedging instrument) (a) Highly probable forecast aluminium sales (Hedged item) Nominal Carrying amount Change in fair value in the period Cash flow hedge reserve (b) US$m Change in fair value in Total hedging Hedge ineffective-ness in the period (c) US$m Amount reclassified from reserves to income statement (d) US$m 2020 1,522 46 23 184 (49) 27 (4) 40 2019 1,656 42 29 196 (50) 36 (7) 19 (a) Aluminium embedded derivatives (forward contracts and options) are contained within certain aluminium smelter electricity purchase contracts. US$66 million (2019: US$66 million) of the carrying value is shown within "Other financial assets" and US$20 million (2019: US$24 million) shown within "Other financial liabilities". (b) The difference between this amount and the total cash flow hedge reserve of the Group (shown in n ote 28) relates to our cash flow hedge on the sterling bond (refer to interest rate risk section). (c) Hedge ineffectiveness is included in net operating costs (raw materials, consumables, repairs and maintenance) in the income statement.
Summary of market price relevant to the aluminum purchase price swaps outstanding	Our commodity derivatives are impacted by changes in market prices. The table below summarises the impact that changes in aluminium market prices have on aluminium forward and option contracts embedded in power supply agreements outstanding at 31 December 2020. Any change in price will result in an offsetting change in our future earnings. Change in 2020 US$m 2019 US$m Effect on net earnings +10 % (19) (28) (10) % 19 27 Effect on equity +10 % (98) (97) (10) % 100 101
Summary of maximum credit risk exposure of the Group's financial assets	The maximum credit risk exposure arising on our financial assets at the balance sheet date is as follows: Note 2020 US$m 2019 US$m Cash and cash equivalents 20 10,381 8,027 Trade and other financial receivables 18 3,286 2,938 Investments 19 2,899 2,839 Derivative assets 19 665 366 Loans to equity accounted units 41 39 Total 17,272 14,209
Summary by currency, the Group's net debt, after taking into account relevant cross currency interest rate swaps and foreign exchange contracts	The table below summarises, by currency, our net debt, after taking into account relevant cross currency interest rate swaps and foreign exchange contracts: Net debt by currency Total Lease liabilities Derivatives Cash and Other Net debt Net debt US dollar (12,102) (342) 248 9,517 2,538 (141) (2,843) Australian dollar (375) (350) — 439 — (286) (561) Euro (4) (25) — 43 — 14 10 South African rand — (1) — 141 — 140 171 Canadian dollar (170) (199) — 36 — (333) (322) Other (2) (261) — 205 — (58) (106) Total (12,653) (1,178) 248 10,381 2,538 (664) (3,651)
Disclosure of effect of changes in foreign exchange rates on earnings	Gains/(losses) associated with 10% strengthening of the US dollar Currency exposure Closing Effect on Of which Impact Australian dollar 77 625 (11) (1,105) Canadian dollar 78 (167) 6 — Euro 123 139 3 — At 31 December 2019 Gains/(losses) associated with 10% strengthening of the US dollar Currency exposure Closing Effect on Of which Impact Australian dollar 70 453 (4) (1,002) Canadian dollar 77 (143) 7 — Euro 112 178 4 —
Disclosure of detailed information about hedges	2020 2019 Nominal amount Nominal amount Maturity Effective Gain in fair value of the interest component of the hedged item Loss in fair value of the interest component of the hedging instrument Loss in fair value of the interest component of the hedged item Gain in fair value of the interest component of the hedging instrument £500 million US$807 million November 2029 1.6132 7 (7) (24) 24 The effective interest rates of our borrowings, impacted by swaps, are summarised below. All nominal values are fully hedged unless otherwise stated: Borrowings in a hedge relationship Nominal value Weighted average Swap maturity Carrying value Carrying value Rio Tinto Finance plc Euro Bonds 2.0% due 2020 (a) 526 3 month LIBOR +1.35% 2020 — 455 Rio Tinto Finance plc Euro Bonds 2.875% due 2024 546 3 month LIBOR +1.64% 2024 555 508 Rio Tinto Finance (USA) Limited Bonds 3.75% 2025 1,200 3 month LIBOR +1.39% 2025 1,299 1,229 Rio Tinto Finance (USA) Limited Bonds 7.125% 2028 750 3 month LIBOR +3.27% 2028 1,005 958 Alcan Inc. Debentures 7.25% due 2028 100 3 month LIBOR +5.43% 2024 109 104 Rio Tinto Finance plc Sterling Bonds 4.0% due 2029 807 3 month LIBOR +2.65% 2024 717 647 Alcan Inc. US$400m Debentures 7.25% due 2031 (b) 400 3 month LIBOR +5.72% 2025 438 — Alcan Inc. US$750m Global Notes 6.125% due 2033 (b) 750 3 month LIBOR +5.67% 2025 744 — Alcan Inc. US$300m Global Notes 5.75% due 2035 (b) 300 3 month LIBOR +5.18% 2025 292 — Rio Tinto Finance (USA) Limited Bonds 5.2% 2040 1,150 3 month LIBOR +3.79% 2022 1,173 1,137 Rio Tinto Finance (USA) plc Bonds 4.75% 2042 500 3 month LIBOR +3.42% 2023 501 483 Rio Tinto Finance (USA) plc Bonds 4.125% 2042 750 3 month LIBOR +2.83% 2023 743 716 (a) On 11 May 2020 we repaid, in full, the nominal amount of the Rio Tinto Finance plc Euro Bonds 2% due 2020. (b) In 2020 we entered into new swaps to convert the interest payable in relation to these bonds from fixed to floating rates.
Summary of fair value of financial instruments	The following table shows the carrying amounts and fair values of our borrowings including those which are not carried at an amount which approximates their fair value at 31 December 2020 and 31 December 2019. The fair values of our cash equivalents, loans to equity accounted units and other financial liabilities approximate their carrying values because of their short maturity, or because they carry floating rates of interest. 2020 2019 Note Carrying Fair Carrying Fair Borrowings 21 12,653 15,076 12,806 14,678 The tables below show the financial instruments by valuation method in accordance with IFRS 9 at 31 December 2020 and 31 December 2019 . Held at fair value At 31 December 2020 Note Total Level 1 (a) US$m Level 2 (b) US$m Level 3 (c) US$m Held at Assets Cash and cash equivalents (d) 10,381 6,411 — — 3,970 Investments in equity shares and funds 75 35 — 40 — Other investments, including loans (e) 19 2,899 2,563 — 198 138 Trade and other financial receivables (f) 18 3,286 5 1,802 — 1,479 Derivatives (net) Forward contracts and option contracts: designated as hedges (g) (Section B) 53 — 7 46 — Forward contracts and option contracts, not designated as hedges (g) (Section B) 180 — 69 111 — Derivatives related to net debt (h) (Section B) 248 — 248 — — Liabilities Trade and other financial payables 24 (5,847) — (30) — (5,817) Total 11,275 9,014 2,096 395 (230) Held at fair value At 31 December 2019 Note Total Level 1 (a) US$m Level 2 (b) US$m Level 3 (c) US$m Held at Assets Cash and cash equivalents (d) 8,027 5,320 — — 2,707 Investments in equity shares and funds 61 26 — 35 — Other investments, including loans (e) 19 2,839 2,607 — 211 21 Trade and other financial receivables (f) 18 2,938 15 1,122 — 1,801 Derivatives (net) Forward contracts and option contracts: designated as hedges (g) (Section B) 42 — — 42 — Forward contracts and option contracts, not designated as hedges (g) (Section B) 120 — 25 95 — Derivatives related to net debt (h) (Section B) (147) — (147) — — Liabilities Trade and other financial payables 24 (5,398) — (57) — (5,341) Total 8,482 7,968 943 383 (812) (a) Valuation is based on unadjusted quoted prices in active markets for identical financial instruments. This category includes listed equity shares and other quoted funds. (b) Valuation is based on inputs that are observable for the financial instruments; which include quoted prices for similar instruments or identical instruments in markets which are not considered to be active, or inputs, either directly or indirectly based on observable market data. (c) Valuation is based on inputs that are not based on observable market data (unobservable inputs). (d) Cash and cash equivalents include money market funds which are treated as fair value through profit or loss (FVPL) under IFRS 9 with the fair value movements going into finance income. (e) Other investments, including loans, comprise: cash deposits in rehabilitation funds, government bonds, managed investment funds and royalty receivables. The royalty receivables are valued based on future expected output as well as forward commodity prices. (f) Trade receivables include provisionally priced invoices. The related revenue is initially based on forward market selling prices for the quotation periods stipulated in the contracts with changes between the provisional price and the final price recorded separately within "Other revenue". The selling price can be measured reliably for the Group's products, as it operates in active and freely traded commodity markets. At 31 December 2020, US$1,671 million (31 December 2019: US$1,040 million) of provisionally priced receivables were recognised. (g) Level 3 derivatives consist of derivatives embedded in electricity purchase contracts linked to the LME with terms expiring between 2025 and 2029 (2019: 2025 and 2030). The embedded derivatives are measured using discounted cash flows and option model valuation techniques.
Summary of changes in the fair value of Level 3 financial assets and financial liabilities	The table below shows the summary of changes in the fair value of the Group's level 3 financial assets and financial liabilities. 2020 Level 3 financial assets and financial liabilities US$m 2019 Level 3 financial assets and financial liabilities US$m Opening balance 383 637 Currency translation adjustments 16 (1) Total realised gains/(losses) included in: – consolidated sales revenue 11 — – net operating costs (39) (7) Total unrealised (losses)/gains included in: – net operating costs 24 (254) Total unrealised gains transferred into other comprehensive income through cash flow hedges 26 28 Additions 1 1 Disposals/maturity of financial instruments (27) (21) Closing balance 395 383 Net losses for the year included in the income statement for assets and liabilities held at year end (a) — (263) (a) In 2020 gains and losses included in the income statement offset each other to the extent that the net result is less than US$1 million.

Contingencies and commitments (

Contingencies and commitments (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Commitments And Contingent Liabilities [Abstract]
Summary of capital commitments	2020 US$m 2019 US$m Capital commitments excluding the Group's share of joint venture capital commitments Within 1 year 3,021 3,069 Between 1 and 3 years 97 851 Between 3 and 5 years — 133 After 5 years 34 — Total 3,152 4,053 Group's share of joint venture capital commitments Within 1 year 9 92 Between 1 and 3 years — 1 Total 9 93
Summary of aggregate amount of future payment commitments under purchase obligations outstanding	The aggregate amount of future payment commitments under purchase obligations outstanding at 31 December was: 2020 US$m 2019 US$m Within 1 year 3,100 2,920 Between 1 and 2 years 1,715 1,705 Between 2 and 3 years 1,291 1,431 Between 3 and 4 years 1,242 1,084 Between 4 and 5 years 848 1,082 After 5 years 8,437 8,697 Total 16,633 16,919
Summary of indemnities and other performance guarantees	2020 US$m 2019 US$m Indemnities and other performance guarantees (a)(b) 146 204 (a) Indemnities and other performance guarantees represent the potential outflow of funds from the Group for the satisfaction of obligations including those under contractual arrangements (for example undertakings related to supplier agreements) not provided for in the balance sheet, where the likelihood of the guarantees or indemnities being called is assessed as possible rather than probable or remote.

Average number of employees (Ta

Average number of employees (Tables)	12 Months Ended
	Dec. 31, 2020
Number and average number of employees [abstract]
Summary of average number of employees	Subsidiaries and joint operations Equity accounted units Group total 2020 2019 2018 2020 2019 2018 2020 2019 2018 Principal locations of employment: Australia and New Zealand 20,482 19,195 19,017 634 619 578 21,116 19,814 19,595 Canada 11,814 11,576 10,620 — — — 11,814 11,576 10,620 UK 172 190 287 — — — 172 190 287 Europe 1,020 959 1,418 — — — 1,020 959 1,418 Africa 2,559 3,121 3,496 1,214 1,250 1,262 3,773 4,371 4,758 US 3,543 3,400 3,792 — — — 3,543 3,400 3,792 Mongolia 3,465 3,215 2,886 — — — 3,465 3,215 2,886 Indonesia — — 1,615 — — — — — 1,615 South America 220 243 210 1,293 1,270 1,289 1,513 1,513 1,499 India 324 272 288 — — — 324 272 288 Singapore 456 430 422 — — — 456 430 422 Other countries (a) 278 267 278 — — — 278 267 278 Total 44,333 42,868 44,329 3,141 3,139 3,129 47,474 46,007 47,458 (a) “Other countries” primarily includes employees in the Middle East (excluding Oman which is included in Africa), and other countries in Asia which are not shown separately in the table above.

Principal subsidiaries Principa

Principal subsidiaries Principal subsidiaries - (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of subsidiaries [abstract]
Principal in subsidiaries	Company and country of incorporation/operation Principal activities Class of shares Proportion of class held (%) Group Non-controlling Australia Argyle Diamonds Limited Mining and processing of diamonds Ordinary 100 100 — Dampier Salt Limited Salt and gypsum production Ordinary 68.36 68.36 31.64 Energy Resources of Australia Ltd (a) Uranium processing Ordinary 86.33 86.33 13.67 Hamersley Iron Pty Limited Iron ore mining Ordinary 100 100 — North Mining Limited (b) Iron ore mining Ordinary 100 100 — Rio Tinto Aluminium (Holdings) Limited Bauxite mining; alumina production; primary aluminium smelting Ordinary 100 100 — Robe River Mining Co Pty Ltd (b) Iron ore mining Class A 40 60 40 Class B 76.36 Brazil Alcan Alumina Ltda. (c) Alumina production and bauxite mining Quota 100 100 — Canada Iron Ore Company of Canada (d) Iron ore mining; iron ore pellets production Common 58.72 58.72 41.28 Rio Tinto Fer et Titane Inc. Titanium dioxide feedstock; high purity iron and steel production Common 100 100 — Class B preference 100 100 — CAD 0.01 preferred 100 100 — Rio Tinto Alcan Inc. Bauxite mining; alumina refining; aluminium smelting Common 100 100 — Diavik Diamond Mines (2012) Inc. (e) Diamond mining and processing Common 100 100 — Guinea Simfer Jersey Limited (f) Iron ore project Ordinary 53 53 47 Madagascar QIT Madagascar Minerals SA (g) Ilmenite mining Common 80 80 15 Investment certificates 100 100 Voting certificates 80 80 20 Mongolia Turquoise Hill Resources Ltd (including Oyu Tolgoi LLC) (h) Copper and gold mining Common 50.79 50.79 49.21 South Africa Richards Bay Titanium (Proprietary) Limited (i) Titanium dioxide; high purity iron production B Ordinary 100 74 26 B preference 100 Parent Preference 100 Richards Bay Mining (Proprietary) Limited (i) Ilmenite, rutile and zircon mining B Ordinary 100 74 26 B preference 100 Parent Preference 100 US Kennecott Holdings Corporation (including Kennecott Utah Copper and Kennecott Exploration) Copper and gold mining, smelting and refining and exploration activities Common US$0.01 100 100 — U.S. Borax Inc. Mining, refining and marketing of borates Common US$0.10 100 100 — This list includes only those companies that have a more significant impact on the profit or operating assets of the Group. Refer to note 44 for a list of related undertakings. 32 Principal subsidiaries continued The Group’s principal subsidiaries are mostly held by intermediate holding companies and not directly by Rio Tinto plc or Rio Tinto Limited. (a) In February 2020, Rio Tinto's interest in Energy Resources of Australia (ERA) increased from 68.4% to 86.3% as a result of new ERA shares issued to Rio Tinto under the Entitlement Offer and Underwriting Agreement to raise funds for the rehabilitation of the Ranger Project Area. (b) Robe River Mining Co Pty Ltd (which is 60% owned by the Group) holds a 30% interest in Robe River Iron Associates (Robe River). North Mining Ltd (which is wholly owned by the Group) holds a 35% interest in Robe River. Through these companies the Group recognises a 65% share of the assets, liabilities, revenues and expenses of Robe River, with a 12% non-controlling interest. The Group therefore has a 53% beneficial interest in Robe River. (c) Alcan Alumina Ltda holds the Group’s 10% interest in Consórcio De Alumínio Do Maranhão, a joint operation in which the Group participates but is not a joint operator. The Group recognises its share of assets, liabilities, revenues and expenses relating to this arrangement. (d) Iron Ore Company of Canada is incorporated in the US, but operates in Canada. (e) Diavik Diamond Mines (2012) Inc. (DDMI) is the legal entity that owns the Group’s 60% interest in the Diavik Joint Venture, an unincorporated arrangement. The Group recognises its share of assets, revenue and expenses relating to this arrangement. Liabilities are recognised according to DDMI’s contractual obligations, with a corresponding 40% receivable or contingent asset representing the co-owner’s share where applicable. (f) Simfer Jersey Limited, a company incorporated in Jersey in which the Group has a 53% interest, has an 85% interest in Simfer S.A., the company that operates the Simandou mining project in Guinea. The Group therefore has a 45.05% indirect interest in Simfer S.A. These entities are consolidated as subsidiaries and together referred to as the Simandou iron ore project. (g) The Group’s shareholding in QIT Madagascar Minerals SA carries an 80% economic interest and 80% of the total voting rights; a further 5% economic interest is held through non-voting investment certificates to give an economic interest of 85%. The non-controlling interests have a 15% economic interest and 20% of the total voting rights. (h) The Group has a 50.79% interest in Turquoise Hill Resources Ltd, which holds a 66% interest in Oyu Tolgoi LLC (OT) which is a subsidiary of Turquoise Hill Resources Ltd. The Group therefore has a 33.5% indirect interest in OT. Turquoise Hill Resources Ltd is incorporated in Canada but operates principally in Mongolia. (i) Additional classes of shares issued by Richards Bay Titanium (Proprietary) Limited and Richards Bay Mining (Proprietary) Limited representing non-controlling interests are not shown. The Group’s total legal and beneficial interest in Richards Bay Titanium (Proprietary) Limited and Richards Bay Mining (Proprietary) Limited is 74% .
Subsidiaries financial information	This summarised financial information is shown on a 100% basis. It represents the amounts shown in the subsidiaries’ financial statements prepared in accordance with IFRS under Group accounting policies, including fair value adjustments, and before intercompany eliminations. Income statement summary for the year ended 31 December Iron Ore Company of Canada 2020 US$m Iron Ore Company of Canada 2019 US$m Energy Resources of Australia 2020 US$m Energy Resources of Australia 2019 US$m Turquoise Hill (j)(k)(l) 2020 US$m Turquoise Hill (j)(k)(l) 2019 US$m Revenue 2,269 2,014 162 145 1,078 1,166 Profit/(loss) after tax 611 543 9 5 357 (2,137) – attributable to non-controlling interests 252 224 3 2 130 (1,490) – attributable to Rio Tinto 359 319 5 3 227 (647) Other comprehensive income 56 57 20 2 2 — Total comprehensive income/(loss) 667 600 29 7 359 (2,137) Balance sheet summary as at 31 December 2020 2019 2020 2019 2020 2019 Non-current assets 2,733 2,585 329 76 10,930 9,589 Current assets 670 610 371 258 1,496 2,449 Current liabilities (462) (532) (176) (127) (540) (493) Non-current liabilities (993) (927) (427) (462) (4,404) (4,405) Net assets/(liabilities) 1,948 1,736 97 (255) 7,482 7,140 – attributable to non-controlling interests 804 718 18 — 2,424 2,369 – attributable to Rio Tinto 1,144 1,018 79 (255) 5,058 4,771 Cash flow statement summary for the year ended 31 December 2020 2019 2020 2019 2020 2019 Cash flow from operations 1,027 1,039 (15) (73) 380 298 Dividends paid to non-controlling interests (180) (228) — — — — (j) Turquoise Hill Resources Ltd holds a controlling interest in Oyu Tolgoi LLC (OT). (k) Under the terms of the project finance facility held by OT, there are certain restrictions on the ability of OT to make shareholder distributions. (l) Since 2011, Turquoise Hill has funded common share investments in OT on behalf of Erdenes Oyu Tolgoi LLC (“Erdenes”). In accordance with the Amended and Restated Shareholders Agreement dated 8 June 2011, such funded amounts earn interest at an effective annual rate of LIBOR plus 6.5% and are repayable to them via a pledge over Erdenes’ share of future OT common share dividends. Erdenes also has the right to reduce the outstanding balance by making payments directly to Turquoise Hill. Common share investments funded on behalf of Erdenes, including accrued interest, are recorded as a reduction to the net carrying value of their component of non-controlling interests. As at 31 December 2020, the cumulative amount of such funding was US$1,378 million (31 December 2019: US$1,241 million), excluding accrued interest of US$804 million (31 December 2019: US$655 million) relating to this funding. Income statement summary for the year ended 31 December Robe River Mining Co Pty Robe River Mining Co Pty Other companies and eliminations (m) 2020 US$m Other companies and eliminations (m) 2019 US$m Robe River 2020 US$m Robe River 2019 US$m Revenue 1,738 1,493 2,028 1,743 3,766 3,236 Profit after tax 939 808 1,019 825 1,958 1,633 – attributable to non-controlling interests 376 312 — — 376 312 – attributable to Rio Tinto 563 496 1,019 825 1,582 1,321 Other comprehensive income/(loss) 294 (13) 136 (12) 430 (25) Total comprehensive income 1,233 795 1,155 813 2,388 1,608 Balance sheet summary as at 31 December 2020 2019 2020 2019 2020 2019 Non-current assets 3,452 2,622 4,247 3,687 7,699 6,309 Current assets 865 1,161 2,239 1,873 3,104 3,034 Current liabilities (380) (173) (414) (303) (794) (476) Non-current liabilities (255) (84) (4,752) (3,392) (5,007) (3,476) Net assets 3,682 3,526 1,320 1,865 5,002 5,391 – attributable to non-controlling interests 1,397 1,404 — — 1,397 1,404 – attributable to Rio Tinto 2,285 2,122 1,320 1,865 3,605 3,987 Cash flow statement summary for the year ended 31 December 2020 2019 2020 2019 2020 2019 Cash flow from operations 1,491 1,255 1,771 1,447 3,262 2,702 Dividends paid to non-controlling interests (332) (139) (165) — (497) (139) (m) "Other companies and eliminations” includes North Mining Limited (a wholly owned subsidiary of the Group which accounts for its interest in Robe River) and goodwill of US$383 million (2019: US$349 million) that arose on the Group’s acquisition of its interest in Robe River.

Principal joint operations (Tab

Principal joint operations (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of joint operations [abstract]
Summary of principle joint operations	Company and country of incorporation/operation Principal activities Group interest (%) Australia Tomago Aluminium Joint Venture Aluminium smelting 51.6 Gladstone Power Station Power generation 42.1 Hope Downs Joint Venture Iron ore mining 50 Queensland Alumina Limited (a) (b) Alumina production 80 Pilbara Iron Arrangements Infrastructure, corporate and mining services (c) New Zealand New Zealand Aluminium Smelters Limited (a) (b) Aluminium smelting 79.4 Canada Aluminerie Alouette Inc. Aluminium production 40 US Pechiney Reynolds Quebec Inc (b) (d) Aluminium smelting 50.2

Principal joint ventures (Table

Principal joint ventures (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of joint ventures [abstract]
Summary of principal joint ventures	Company and country of incorporation/operation Principal activities Number of Class of Proportion Group Chile Minera Escondida Ltda (a) Copper mining and refining — — — 30 Oman Sohar Aluminium Co. L.L.C. (b) Aluminium smelting; power generation 37,500 Ordinary 20 20 This list includes only those joint ventures that have a more significant impact on the profit or operating assets of the Group. Refer to note 44 for a list of related undertakings. The Group’s principal joint ventures are held by intermediate holding companies and not directly by Rio Tinto plc or Rio Tinto Limited. (a) Although the Group has a 30% interest in Minera Escondida Ltda, participant and management agreements provide for an Owners’ Council whereby significant commercial and operational decisions about the relevant activities that significantly affect the returns that are generated in effect require the joint approval of both Rio Tinto and BHP Billiton (holders of a 57.5% interest). It is therefore determined that Rio Tinto has joint control. The year end of Minera Escondida Ltda is 30 June. The amounts included in the consolidated financial statements of Rio Tinto are, however, based on accounts of Minera Escondida Limitada that are coterminous with those of the Group. (b) Although the Group holds a 20% interest in Sohar Aluminium Co. L.L.C, decisions about relevant activities that significantly affect the returns that are generated require agreement of all parties to the arrangement. It is therefore determined that Rio Tinto has joint control. This summarised financial information is shown on a 100% basis. It represents the amounts shown in the joint ventures’ financial statements prepared in accordance with IFRS under Group accounting policies, including fair value adjustments and amounts due to and from Rio Tinto. Minera Escondida Ltda (c) 2020 US$m Minera Escondida Ltda (c) 2019 US$m Sohar Aluminum Co.L.L.C. (d) 2020 US$m Sohar Aluminum Co.L.L.C. (d) 2019 US$m Revenue 7,650 7,120 640 715 Depreciation and amortisation (1,427) (1,693) (115) (115) Impairment charges (note 6) — — (1,100) — Other operating costs (2,756) (3,670) (430) (505) Operating profit/(loss) 3,467 1,757 (1,005) 95 Finance expense (137) (157) (20) (35) Income tax (1,197) (627) (15) (10) Profit/(loss) after tax 2,133 973 (1,040) 50 Other comprehensive loss (40) (17) — — Total comprehensive income/(loss) 2,093 956 (1,040) 50 Non-current assets 11,833 12,450 1,850 3,045 Current assets 3,107 2,250 270 290 Current liabilities (1,813) (1,827) (675) (205) Non-current liabilities (4,560) (4,670) (200) (845) Net assets 8,567 8,203 1,245 2,285 Assets and liabilities above include: – cash and cash equivalents 1,103 603 30 20 – current financial liabilities (790) (807) (565) (110) – non-current financial liabilities (2,560) (2,380) (30) (675) Dividends received from joint venture (Rio Tinto share) 585 666 — — Reconciliation of the above amounts to the investment recognised in the Group balance sheet Group interest 30% 30% 20% 20% Net assets 8,567 8,203 1,245 2,285 Group’s ownership interest 2,570 2,461 249 457 Carrying value of Group’s interest 2,570 2,461 249 457 (c) In addition to its “Investment in equity accounted units”, the Group recognises deferred tax liabilities of US$358 million (2019: US$362 million) relating to tax on unremitted earnings of equity accounted units. (d) Under covenants stipulated in the agreement to Sohar Aluminium Co. L.L.C.’s secured loan facilities, Sohar Aluminium Co. L.L.C. is currently restricted from making any shareholder distributions until 2021 unless a specified amount of the loan facilities is funded.

Principal associates (Tables)

Principal associates (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of associates [abstract]
Summary of principal associates	At 31 December 2020 Company and country of incorporation/operation Principal activities Number of Class of Proportion Group Australia Boyne Smelters Limited (a) Aluminium smelting 153,679,560 Ordinary 59.4 59.4 Brazil Mineração Rio do Norte S.A. (b) Bauxite mining 25,000,000,000 Ordinary 12.5 12 47,000,000,000 Preferred 11.75 US Halco (Mining) Inc. (c) Bauxite mining 4,500 Common 45 45 This list includes only those associates that have a more significant impact on the profit or operating assets of the Group. Refer to note 44 for a list of related undertakings. The Group’s principal associates are held by intermediate holding companies and not directly by Rio Tinto plc or Rio Tinto Limited. (a) The parties that collectively control Boyne Smelters Limited do so through decisions that are determined on an aggregate voting interest that can be achieved by several combinations of the parties. Although each combination requires Rio Tinto’s approval, this is not joint control as defined under IFRS 11. Rio Tinto is therefore determined to have significant influence over this company. (b) Although the Group holds only 12% of Mineração Rio do Norte S.A., it has representation on its board of directors and a consequent ability to participate in the financial and operating policy decisions. It is therefore determined that Rio Tinto has significant influence. (c) Halco (Mining) Inc. has a 51% indirect interest in Compagnie des Bauxites de Guinée, a bauxite mine, the core assets of which are located in Guinea . Summary information for associates that are material to the Group This summarised financial information is shown on a 100% basis. It represents the amounts shown in the associate’s financial statements prepared in accordance with IFRS under Group accounting policies, including fair value adjustments and amounts due to and from Rio Tinto. Boyne Smelters Limited (a) 2020 US$m Boyne Smelters Limited (a) 2019 US$m Revenue — — Loss after tax (b) (198) (7) Other comprehensive income/(loss) (c) 30 (3) Total comprehensive loss (168) (10) Non-current assets 1,037 1,229 Current assets 98 96 Current liabilities (146) (114) Non-current liabilities (779) (814) Net assets 210 397
Reconciliation of financial information for principal associates by carrying value	Reconciliation of the above amount to the investment recognised in the Group balance sheet Group interest 59.4% 59.4% Net assets 210 397 Group's ownership interest 125 236 Loans to equity accounted units 112 113 Carrying value of Group's interest 237 349 (a) Boyne Smelters Limited is a tolling operation; as such it is dependent on its participants for funding which is provided through cash calls. Rio Tinto has made certain prepayments to Boyne for toll processing of alumina. These are charged to Group operating costs as processing takes place. (b) In 2020, includes US$200 million of impairment changes. Refer to note 6. (c) "Other comprehensive income/(loss)” is net of amounts recognised by subsidiaries in relation to quasi equity loans.
Summary information for joint ventures and associates that are not individually material to the group	Summary information for joint ventures and associates that are not individually material to the Group Associates 2020 US$m Associates 2019 US$m Carrying value of Group's interest 708 704 Profit after tax — 3 Other comprehensive income (5) 10 Total comprehensive income (5) 13

Directors' and key management_2

Directors' and key management remuneration (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Information About Key Management Personnel [Abstract]
Summary of aggregate remuneration	Aggregate remuneration, calculated in accordance with the UK Companies Act 2006, of the directors of the parent companies was as follows: 2020 US$'000 2019 US$'000 2018 US$'000 Emoluments 6,686 7,524 9,069 Long-term incentive plans 8,974 4,748 2,923 15,660 12,272 11,992 Pension contributions: defined contribution plans 29 42 80 Gains made on exercise of share options — — 107
Summary of aggregate compensation, representing the expense	Aggregate compensation, representing the expense recognised under IFRS, as defined in note 1, of the Group’s key management, including directors, was as follows: 2020 US$'000 2019 US$'000 2018 US$'000 Short-term employee benefits and costs 21,685 22,075 23,978 Post-employment benefits 369 477 629 Employment termination benefits 2,789 310 69 Share-based payments 34,954 17,632 14,916 Total 59,797 40,494 39,592

Auditors' remuneration (Tables)

Auditors' remuneration (Tables)	12 Months Ended
	Dec. 31, 2020
Auditor's remuneration [abstract]
Auditors' remuneration	2020 US$m 2019 US$m 2018 US$m Audit of the Group 11.0 9.6 9.2 Audit of subsidiaries 6.3 6.8 7.5 Total audit 17.3 16.4 16.7 Audit-related assurance service 0.8 0.8 0.9 Other assurance services (b) 1.4 1.9 3.3 Total assurance services 2.2 2.7 4.2 Tax compliance — 0.1 — Other non-audit services not covered above 0.1 — 0.2 Total non-audit services 2.3 2.8 4.4 Total Group auditors’ remuneration 19.6 19.2 21.1 Audit fees payable to other accounting firms Audit of the financial statements of the Group’s subsidiaries (c) 0.6 1.4 1.4 Fees in respect of pension scheme audits 0.1 0.1 0.1 Total audit fees payable to other accounting firms 0.7 1.5 1.5 (a) In 2020, all amounts were paid to member firms of KPMG. In 2019 and 2018, all amounts were paid to member firms of PwC, being the Group's auditors for these financial years. The remuneration payable to KPMG, the Group auditors, is approved by the Audit Committee. The Committee sets the policy for the award of non-audit work to the auditors and approves the nature and extent of such work, and the amount of the related fees, to ensure that independence is maintained. The fees disclosed above consolidate all payments made to member firms of KPMG by the companies and their subsidiaries, along with fees in respect of joint operations paid for by the Group and includes an estimate of the costs to complete the 2020 audit. Non-audit services arise largely from assurance and/or regulation related work. (b) Other assurance services relates to the review of non-statutory financial information including sustainability reporting. (c) In 2019 and 2018 these amounts include fees payable to KPMG in respect of subsidiaries who's statutory auditor was KPMG prior to their appointment as the Group's auditor.

Related-party transactions (Tab

Related-party transactions (Tables)	12 Months Ended
	Dec. 31, 2020
Related party transactions [abstract]
Summary of transactions and balances with equity accounted units	2020 US$m 2019 US$m 2018 US$m Income statement items Purchases from equity accounted units (960) (1,155) (1,209) Sales to equity accounted units 271 268 493 Cash flow statement items Dividends from equity accounted units 594 669 800 Net funding of equity accounted units (43) (33) (9) Balance sheet items Investments in equity accounted units (a) 15 3,764 3,971 4,299 Loans to equity accounted units 19 41 39 38 Trade and other receivables: amounts due from equity accounted units (b) 18 251 259 278 Trade and other payables: amounts due to equity accounted units 24 (241) (271) (223) (a) Investments in equity accounted units include quasi equity loans. Further information about investments in equity accounted units is set out in not es 34 and 35.

Exchange rates in US$ (Tables)

Exchange rates in US$ (Tables)	12 Months Ended
	Dec. 31, 2020
Foreign exchange rates [abstract]
Summary of principal exchange rate used in preparation of financial statements	The principal exchange rates used in the preparation of the 2020 financial statements were: Full-year average Year-end 2020 2019 2018 2020 2019 2018 Sterling 1.28 1.28 1.34 1.36 1.31 1.27 Australian dollar 0.69 0.70 0.75 0.77 0.70 0.70 Canadian dollar 0.75 0.75 0.77 0.78 0.77 0.73 Euro 1.14 1.12 1.18 1.23 1.12 1.14 South African rand 0.061 0.069 0.076 0.068 0.071 0.069

Share-based payments (Tables)

Share-based payments (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of terms and conditions of share-based payment arrangement [line items]
Charge has been recognised in income statement for Rio Tinto's share-based incentive plans, and the related liability (for cash-settled plans)	The charge that has been recognised in the income statement for Rio Tinto’s share-based incentive plans, and the related liability (for cash-settled awards), is set out in the table below. Charge recognised for the year Liability at the end of the year 2020 US$m 2019 US$m 2018 US$m 2020 US$m 2019 US$m Equity-settled awards 131 118 118 — — Cash-settled awards 7 5 4 7 19 Total 138 123 122 7 19
Performance share plans
Disclosure of terms and conditions of share-based payment arrangement [line items]
Summary of non-vested and vested shares	Rio Tinto plc awards Rio Tinto Limited awards 2020 number Weighted average fair value at grant date 2020 £ 2019 number Weighted average fair value at grant date 2019 £ 2020 number Weighted average fair value at grant date 2020 A$ 2019 number Weighted average fair value at grant date 2019 A$ Unvested awards at 1 January 3,803,394 22.20 3,845,082 21.86 1,636,517 45.11 1,797,279 43.34 Awarded 716,111 13.55 755,735 24.68 198,863 33.56 297,189 54.55 Forfeited (136,030) 21.13 (122,961) 23.95 (178,921) 46.37 (126,775) 44.02 Failed performance conditions (145,661) 16.64 (384,130) 23.79 (63,852) 33.38 (188,956) 46.42 Vested (459,773) 20.55 (290,332) 21.36 (201,234) 41.21 (142,220) 41.72 Unvested awards at 31 December 3,778,041 21.01 3,803,394 22.20 1,391,373 44.40 1,636,517 45.11 Rio Tinto plc awards Rio Tinto Limited awards 2020 number Weighted average fair value at grant date 2020 £ 2019 number Weighted average fair value at grant date 2019 £ 2020 number Weighted average fair value at grant date 2020 A$ 2019 number Weighted average fair value at grant date 2019 A$ Vested awards settled in shares during the year (including dividend shares applied on vesting) 476,602 43.13 339,821 45.52 217,287 93.48 151,607 100.30 Vested awards settled in cash during the year (including dividend shares applied on vesting) 108,887 43.13 1,279 43.65 28,208 93.82 1,347 92.97
Share Incentive Plans
Disclosure of terms and conditions of share-based payment arrangement [line items]
Summary of non-vested and vested shares	Rio Tinto plc awards (a) Rio Tinto Limited awards 2020 number Weighted average fair value at grant date 2020 £ 2019 number Weighted average fair value at grant date 2019 £ 2020 number Weighted average fair value at grant date 2020 A$ 2019 number Weighted average fair value at grant date 2019 A$ Unvested awards at 1 January (b) 2,613,013 37.14 3,042,020 31.43 2,273,669 75.46 2,613,930 61.71 Awarded 1,190,528 36.27 1,043,817 40.41 921,070 83.20 846,008 86.56 Forfeited (99,038) 44.42 (224,402) 39.46 (60,935) 85.01 (174,025) 72.18 Cancelled (33,955) 37.72 (24,043) 32.87 (50,354) 71.45 (35,481) 60.91 Vested (1,019,687) 34.46 (1,224,379) 25.40 (866,716) 65.19 (976,763) 49.39 Unvested awards at 31 December (b) 2,650,861 37.50 2,613,013 37.14 2,216,734 82.52 2,273,669 75.46 Comprising: – Management Share Awards 1,352,759 38.73 1,398,039 38.68 1,291,203 85.80 1,363,601 78.67 – Bonus Deferral Awards 211,905 36.14 192,878 41.95 53,324 85.53 87,930 87.81 – Global Employee Share Plan 1,050,608 36.06 982,932 33.98 872,207 77.47 822,138 68.82 – UK Share Plan 35,589 41.54 39,164 37.86 — — — — 2020 number Weighted average fair value at grant date 2020 £ 2019 number Weighted average fair value at grant date 2019 £ 2020 number Weighted average fair value at grant date 2020 A$ 2019 number Weighted average fair value at grant date 2019 A$ Vested awards settled in shares during the year (including dividend shares applied on vesting): – Management Share Awards 707,133 42.26 681,242 43.68 640,948 97.74 582,948 93.05 – Bonus Deferral Awards 111,233 49.71 163,076 42.53 63,404 101.96 85,142 97.30 – Global Employee Share Plan 401,169 43.82 543,426 43.04 299,381 98.60 421,614 91.50 – UK Share Plan 2,392 45.73 34,196 42.21 — — — — Vested awards settled in cash during the year (including dividend shares applied on vesting): – Bonus Deferral Awards 19,617 48.34 — — — — — —

Post-retirement benefits (Table

Post-retirement benefits (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of information about defined benefit plans [abstract]
Summary of fair value of plan assets	The proportions of the total fair value of assets in the pension plans for each asset class at the balance sheet date were: 2020 2019 Equities 21.1 % 20.4 % – Quoted 17.9 % 17.0 % – Private 3.2 % 3.4 % Bonds 55.8 % 63.4 % – Government fixed income 17.7 % 18.4 % – Government inflation-linked 9.6 % 16.2 % – Corporate and other publicly quoted 22.6 % 24.1 % – Private 5.9 % 4.7 % Property 7.5 % 8.8 % – Quoted property funds 3.1 % 3.4 % – Unquoted property funds 4.4 % 5.4 % Qualifying insurance policies 11.3 % 3.1 % Cash & other 4.3 % 4.3 % Total 100.0 % 100.0 %
Summary of maturity of defined benefit obligations	An approximate analysis of the maturity of the obligations is given in the table below: Pension Other 2020 Total 2019 Total 2018 Total Proportion relating to current employees 21 % 19 % 21 % 20 % 19 % Proportion relating to former employees not yet retired 12 % 0 % 11 % 12 % 11 % Proportion relating to retirees 67 % 81 % 68 % 68 % 70 % Total 100 % 100 % 100 % 100 % 100 % Average duration of obligations (years) 14.4 13.5 14.3 14.4 13.4
Summary of geographical distribution of defined benefit obligations	An approximate analysis of the geographic distribution of the obligations is given in the table below: Pension Other 2020 Total 2019 Total 2018 Total Canada 54 % 46 % 53 % 53 % 48 % UK 30 % 2 % 28 % 28 % 28 % US 7 % 50 % 10 % 10 % 14 % Switzerland 5 % 0 % 5 % 5 % 5 % Other 4 % 2 % 4 % 4 % 5 % Total 100 % 100 % 100 % 100 % 100 %
Summary of total expense recognised in the income statement	Total expense recognised in the income statement Pension Other 2020 Total US$m 2019 Total US$m 2018 Total US$m Current employer service cost for defined benefit plans (131) (6) (137) (125) (165) Past service cost (2) — (2) — (36) Curtailment gains — — — — 2 Settlement (losses)/gains (1) — (1) 51 5 Net interest on net defined benefit liability (22) (27) (49) (58) (79) Non-investment expenses paid from the plans (16) — (16) (14) (15) Total defined benefit expense (172) (33) (205) (146) (288) Current employer service cost for defined contribution and industry-wide plans (262) (2) (264) (238) (244) Total expense recognised in the income statement (434) (35) (469) (384) (532)
Summary of total amount recognised in other comprehensive income before tax	Total amount recognised in other comprehensive income before tax 2020 US$m 2019 US$m 2018 US$m Actuarial (losses)/gains (1,242) (1,295) 1,382 Return on assets, net of interest on assets 768 1,033 (527) Gain on application of asset ceiling — — 52 Total (loss)/gain recognised in other comprehensive income (474) (262) 907
Summary of amount recognised in balance sheet	The following amounts were measured in accordance with IAS 19 at 31 December: Pension Other 2020 Total US$m 2019 Total US$m Total fair value of plan assets 14,905 — 14,905 13,923 Present value of obligations – funded (15,731) — (15,731) (14,311) Present value of obligations – unfunded (479) (968) (1,447) (1,342) Present value of obligations – total (16,210) (968) (17,178) (15,653) Net deficit to be shown in the balance sheet (1,305) (968) (2,273) (1,730) Comprising: – Deficits (2,087) (968) (3,055) (2,714) – Surpluses 782 — 782 984 Net deficits on pension plans (1,305) — (1,305) (831) Unfunded post-retirement healthcare obligation — (968) (968) (899)
Summary of funding policy and contributions to plans	Pension Other 2020 Total US$m 2019 Total US$m 2018 Total US$m Contributions to defined benefit plans 169 32 201 257 248 Contributions to defined contribution plans 259 2 261 235 244 Total 428 34 462 492 492
Summary of movement in net defined benefit liability	A summary of the movement in the net defined benefit liability is shown in the first table below. The subsequent tables provide a more detailed analysis of the movements in the present value of the obligations and the fair value of assets. Pension Other 2020 Total US$m 2019 Total US$m Change in the net defined benefit liability Net defined benefit liability at the start of the year (831) (899) (1,730) (1,551) Amounts recognised in income statement (172) (33) (205) (146) Amounts recognised in other comprehensive income (416) (58) (474) (262) Employer contributions 169 32 201 257 Arrangements added/divested — — — (5) Assets transferred to defined contribution section (3) — (3) (3) Currency exchange rate (loss) (52) (10) (62) (20) Net defined benefit liability at the end of the year (1,305) (968) (2,273) (1,730) Pension Other 2020 Total US$m 2019 Total US$m Change in present value of obligation Present value of obligation at the start of the year (14,754) (899) (15,653) (14,754) Current employer service costs (131) (6) (137) (125) Past service cost (2) — (2) — Settlements 6 — 6 638 Interest on obligation (357) (27) (384) (476) Contributions by plan participants (22) — (22) (23) Benefits paid 746 32 778 862 Experience gains 46 15 61 111 Changes in financial assumptions (loss) (1,357) (85) (1,442) (1,447) Changes in demographic assumptions gain 127 12 139 41 Arrangements (added) — — — (5) Currency exchange rate (loss) (512) (10) (522) (475) Present value of obligation at the end of the year (16,210) (968) (17,178) (15,653) 42 Post-retirement benefits continued Pension Other 2020 Total US$m 2019 Total US$m Change in plan assets Fair value of plan assets at the start of the year 13,923 — 13,923 13,203 Settlements (7) — (7) (587) Interest on assets 335 — 335 418 Contributions by plan participants 22 — 22 23 Contributions by employer 169 32 201 257 Benefits paid (746) (32) (778) (862) Non-investment expenses (16) — (16) (14) Return on plan assets, net of interest on assets 768 — 768 1,033 Assets transferred to defined contribution section (3) — (3) (3) Currency exchange rate gain 460 — 460 455 Fair value of plan assets at the end of the year 14,905 — 14,905 13,923
Summary of main assumptions rate for valuations of plans and sensitivity analysis	The main assumptions for the valuations of the plans under IAS 19 are set out below. Where there are multiple plans in a country the rates below are weighted-average figures. Canada UK US Switzerland At 31 December 2020 Discount rate 2.5 % 1.2 % 2.2 % 0.1 % Inflation (a) 1.6 % 2.9 % 2.1 % 0.9 % Rate of increase in pensions 0.1 % 2.5 % — % 0.5 % Rate of increase in salaries 2.8 % 3.6 % 3.6 % 1.9 % At 31 December 2019 Discount rate 3.1 % 2.0 % 3.1 % 0.2 % Inflation (a) 1.6 % 2.9 % 2.0 % 1.1 % Rate of increase in pensions 0.1 % 2.5 % — % 0.2 % Rate of increase in salaries 2.8 % 3.5 % 3.5 % 2.1 % (a) The inflation assumption shown for the UK is for the Retail Price Index. The assumption for the Consumer Price Index at 31 December 2020 was 2.1% (2019: 2.0%). 2020 2019 Approximate Approximate Assumption Change in assumption Pensions Other Pensions Other Discount rate Increase of 0.5 percentage points 988 62 894 56 Decrease of 0.5 percentage points (1,186) (66) (1,057) (60) Inflation Increase of 0.5 percentage points (484) (19) (447) (17) Decrease of 0.5 percentage points 450 17 422 15 Salary increases Increase of 0.5 percentage points (81) (1) (55) (1) Decrease of 0.5 percentage points 72 1 54 1 Demographic – allowance for future improvements in longevity Participants assumed to have the mortality rates of individuals who are one year older 520 19 443 18 Participants assumed to have the mortality rates of individuals who are one year younger (562) (19) (465) (18)

Rio Tinto financial informati_2

Rio Tinto financial information by business unit (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of changes in accounting policies, accounting estimates and errors [Abstract]
Disclosure of financial information by business unit	Gross revenue (a) for the year ended 31 December Underlying EBITDA (b) for the year ended 31 December Net earnings (c) for the year ended 31 December Rio Tinto 2020 US$m 2019 US$m 2018 US$m 2020 US$m 2019 US$m 2018 US$m 2020 US$m 2019 US$m 2018 US$m Iron Ore Pilbara (d) 27,027 23,681 18,359 18,896 15,936 11,267 11,551 9,619 6,460 Dampier Salt 68.4 252 271 246 43 75 56 12 27 18 Evaluation projects/other (e) 657 123 126 (32) 87 55 (112) (8) 53 Intra-segment (e) (428) — — (70) — — (53) — — Total Iron Ore 27,508 24,075 18,731 18,837 16,098 11,378 11,398 9,638 6,531 Aluminium (f) Bauxite 2,302 2,490 2,364 943 1,045 852 434 498 466 Alumina 2,233 2,720 3,423 262 567 808 92 247 390 Primary Metal 4,489 4,940 6,468 904 755 1,418 169 40 595 Pacific Aluminium 1,944 2,204 2,541 112 (22) 148 (6) (137) — Intra-segment and other (2,510) (3,079) (4,084) 6 30 (92) (159) 21 (69) Integrated operations 8,458 9,275 10,712 2,227 2,375 3,134 530 669 1,382 Other product group items 856 1,065 1,479 7 16 17 (5) 10 11 Product group operations 9,314 10,340 12,191 2,234 2,391 3,151 525 679 1,393 Evaluation projects/other — — — (82) (106) (56) (54) (80) (46) Total Aluminium 9,314 10,340 12,191 2,152 2,285 3,095 471 599 1,347 Copper & Diamonds Rio Tinto Kennecott 100.0 1,529 1,879 1,862 588 843 785 149 397 293 Escondida 30.0 2,296 2,136 2,274 1,462 1,034 1,301 650 325 506 Grasberg joint venture (h) — — 457 — — 281 — — 217 Oyu Tolgoi and Turquoise Hill (i) 1,078 1,166 1,180 390 357 375 160 25 69 Diamonds (j) 459 619 695 83 151 301 9 (21) 118 Product group operations 5,362 5,800 6,468 2,523 2,385 3,043 968 726 1,203 Evaluation projects/other 66 15 — (351) (312) (267) (205) (172) (149) Total Copper & Diamonds 5,428 5,815 6,468 2,172 2,073 2,776 763 554 1,054 Energy & Minerals Rio Tinto Coal Australia (k) — — 989 — — 893 — — 591 Iron Ore Company of Canada 58.7 2,444 2,189 1,583 1,130 1,024 586 383 332 166 Rio Tinto Iron & Titanium (l) 1,651 1,938 1,782 476 611 510 216 254 174 Rio Tinto Borates 100.0 564 593 622 126 180 197 65 96 111 Uranium (m) 303 375 415 24 55 18 6 25 (4) Product group operations 4,962 5,095 5,391 1,756 1,870 2,204 670 707 1,038 Simandou iron ore project (n) — — — (14) (12) (15) (6) (5) (7) Evaluation projects/other 52 55 60 (96) (96) (49) (87) (91) (36) Total Energy & Minerals 5,014 5,150 5,451 1,646 1,762 2,140 577 611 995 Other operations (o) 18 18 9 — (77) (70) (54) (89) (102) Inter-segment transactions (264) (31) (15) (94) (9) — (32) (3) — Product group total 47,018 45,367 42,835 24,713 22,132 19,319 13,123 11,310 9,825 Central pension costs, share-based payments and insurance 72 59 (128) 81 60 (90) Restructuring, project and one-off costs (133) (183) (272) (108) (94) (190) Central costs (500) (496) (552) (418) (550) (410) Exploration and evaluation (250) (315) (231) (216) (231) (193) Net interest (14) (122) (134) Underlying EBITDA/earnings 23,902 21,197 18,136 12,448 10,373 8,808 Items excluded from underlying EBITDA/earnings (395) (722) 5,127 (2,679) (2,363) 4,830 Reconciliation to Group income statement Share of equity accounted unit sales and intra-subsidiary/equity accounted unit sales (2,407) (2,202) (2,313) Impairment charges (1,272) (3,487) (132) Depreciation and amortisation in subsidiaries excluding capitalised depreciation (4,074) (4,272) (3,909) Depreciation and amortisation in equity accounted units (576) (653) (650) Taxation and finance items in equity accounted units (443) (296) (372) Finance items (1,751) (648) (33) Consolidated sales revenue/profit before taxation/net earnings 44,611 43,165 40,522 15,391 11,119 18,167 9,769 8,010 13,638 Capital expenditure (o) for the year ended 31 December Depreciation and Operating assets (p) as at 31 December Employees Rio Tinto interest % 2020 US$m 2019 US$m 2018 US$m 2020 US$m 2019 US$m 2018 US$m 2020 US$m 2019 US$m 2018 US$m 2020 2019 2018 Iron Ore Pilbara (d) 2,919 1,720 1,288 1,819 1,704 1,682 16,253 13,865 14,486 11,522 10,634 10,422 Dampier Salt 68.4 22 21 14 19 19 20 163 152 165 351 347 239 Evaluation projects/other (e) — — — — — — 338 2 2 10 — — Intra-segment (e) — — — — — — (104) — — — — — Total Iron Ore 2,941 1,741 1,302 1,838 1,723 1,702 16,650 14,019 14,653 11,883 10,981 10,661 Aluminium (f) Bauxite 142 387 953 290 286 165 2,593 2,597 2,494 2,853 2,940 2,676 Alumina 228 282 218 138 187 194 2,294 2,009 2,721 2,383 2,269 2,009 Primary Metal 602 658 595 643 682 615 9,361 9,674 9,306 6,282 6,357 6,497 Pacific Aluminium 114 129 115 119 154 149 455 970 1,156 2,469 2,356 2,278 Intra-segment and other (1) — — 1 — (1) 662 780 769 141 127 180 Integrated operations 1,085 1,456 1,881 1,191 1,309 1,122 15,365 16,030 16,446 14,128 14,049 13,640 Other product group items (g) — — (508) — — — — — — — — — Product group operations 1,085 1,456 1,373 1,191 1,309 1,122 15,365 16,030 16,446 14,128 14,049 13,640 Evaluation projects/other — — — — 3 — — — — — — — Total Aluminium 1,085 1,456 1,373 1,191 1,312 1,122 15,365 16,030 16,446 14,128 14,049 13,640 Copper & Diamonds Rio Tinto Kennecott 100.0 618 444 318 472 457 427 2,317 2,012 1,864 2,171 2,066 1,993 Escondida 30.0 178 315 302 428 508 518 2,726 2,871 3,057 1,124 1,068 1,087 Grasberg joint venture (h) — — 171 — — 30 — — — — — 1,615 Oyu Tolgoi and Turquoise Hill (i) 1,038 1,289 1,284 189 208 219 8,111 6,780 6,072 3,450 3,152 2,863 Diamonds (j) 25 38 64 60 144 118 (7) 195 267 885 940 967 Product group operations 1,859 2,086 2,139 1,149 1,317 1,312 13,147 11,858 11,260 7,630 7,226 8,525 Evaluation projects/other 5 1 11 4 3 5 192 152 129 159 150 146 Total Copper & Diamonds 1,864 2,087 2,150 1,153 1,320 1,317 13,339 12,010 11,389 7,789 7,376 8,671 Energy & Minerals Rio Tinto Coal Australia (k) — — 32 — — 34 — — (837) — — 1,005 Iron Ore Company of Canada 58.7 243 255 189 170 172 154 1,009 803 975 2,716 2,617 2,397 Rio Tinto Iron & Titanium (l) 144 249 169 173 193 201 3,390 3,507 3,390 4,151 4,115 4,058 Rio Tinto Borates 100.0 42 43 44 49 60 62 502 525 518 966 924 980 Uranium (m) — 5 8 — 3 4 (71) (363) (406) 364 857 1,324 Product group operations 429 552 442 392 428 455 4,830 4,472 3,640 8,197 8,513 9,764 Simandou iron ore project (n) (2) (1) — — — — 16 20 15 69 74 70 Evaluation projects/other 1 — — — — — 33 37 41 77 53 33 Total Energy & Minerals 428 551 442 392 428 455 4,879 4,529 3,696 8,343 8,640 9,867 Other operations (o) 2 (4) 12 199 177 26 (479) (83) (442) 124 159 187 Inter-segment transactions 129 127 129 Product group total 6,320 5,831 5,279 4,773 4,960 4,622 49,883 46,632 45,871 42,267 41,205 43,026 Net assets of disposal groups held for sale (r) — — 440 Other items 79 64 65 82 77 43 (2,165) (2,449) (2,880) 5,207 4,802 4,432 Less: equity accounted units (255) (456) (500) (576) (653) (650) — — — — — — Total 6,144 5,439 4,844 4,279 4,384 4,015 47,718 44,183 43,431 47,474 46,007 47,458 Add back: Proceeds from disposal of property, plant and equipment 45 49 586 Total capital expenditure per cash flow statement 6,189 5,488 5,430 Less: Net (debt)/cash (664) (3,651) 255 Equity attributable to owners of Rio Tinto 47,054 40,532 43,686

Principal accounting policies -

Principal accounting policies - Additional information (Detail) $ in Millions, $ in Billions	1 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2020USD ($)Operation	Dec. 31, 2019USD ($)	Dec. 31, 2020AUD ($)	Dec. 31, 2018USD ($)
Disclosure of initial application of standards or interpretations [Line Items]
Credit derivative, nominal amount		$ 7,300
Materiality threshold		550	$ 350
Trade payables		$ 3,125	2,855
Number of operations | Operation		10
Increase in closure and environmental liabilities		$ 74	444
Operations in closure, monitoring and remediation, cost estimation period		30 years
Decreasing provision		$ 1,200
Provisions		$ 17,665	$ 15,103		$ 13,608
Risk free rate decrease	0.50%
Risk free interest rate on provisions	1.50%	1.50%	2.00%
Onerous contracts provision		$ 219	$ 284
Intragroup loans				$ 14
Non-cancellable operating lease commitments not expected to be charged against EBITDA		$ 2,000
Oyu Tolgoi
Disclosure of initial application of standards or interpretations [Line Items]
Proportion of indirect ownership interest in subsidiary		33.50%
Turquoise Hill Resources Ltd(including Oyu Tolgoi LLC)
Disclosure of initial application of standards or interpretations [Line Items]
Group interest (%)		50.80%
Erdenes Oyu Tolgoi LLC | Floating interest rate
Disclosure of initial application of standards or interpretations [Line Items]
Borrowings, interest rate basis		6.50%		6.50%
Close down and restoration/ environmental
Disclosure of initial application of standards or interpretations [Line Items]
Provisions		$ 13,335	11,090
Trade Payables Subject To Early Settlement Election
Disclosure of initial application of standards or interpretations [Line Items]
Trade payables		$ 551	573
Escondida Joint Venture
Disclosure of initial application of standards or interpretations [Line Items]
Decrease in investment in Escondida Joint Venture			$ 138
Rio Tinto Kennecott
Disclosure of initial application of standards or interpretations [Line Items]
Operations with remaining lives		10 years
Environmental loss contingencies, gross		$ 600

Operating segments - Summary of

Operating segments - Summary of gross sales revenue within the reportable segments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 44,611	$ 43,165	$ 40,522
Other Operations
Disclosure of operating segments [Line Items]
Consolidated sales revenue	18	18	9
Product group
Disclosure of operating segments [Line Items]
Consolidated sales revenue	47,018	45,367	42,835
Share of equity accounted unit sales and intra-subsidiary/equity accounted unit sales
Disclosure of operating segments [Line Items]
Sales revenue	(2,407)	(2,202)	(2,313)
Operating segments | Reportable segments
Disclosure of operating segments [Line Items]
Consolidated sales revenue	47,264	45,380	42,841
Operating segments | Iron Ore
Disclosure of operating segments [Line Items]
Consolidated sales revenue	27,508	24,075	18,731
Operating segments | Aluminium
Disclosure of operating segments [Line Items]
Consolidated sales revenue	9,314	10,340	12,191
Operating segments | Copper & Diamonds
Disclosure of operating segments [Line Items]
Consolidated sales revenue	5,428	5,815	6,468
Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Consolidated sales revenue	5,014	5,150	5,451
Inter-segment transactions
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ (264)	$ (31)	$ (15)

Operating segments - Summary _2

Operating segments - Summary of capital expenditure within the reportable segments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [Line Items]
Capital expenditure	$ 6,144	$ 5,439	$ 4,844
Sales of property, plant and equipment and intangible assets	45	49	586
Capital expenditure per cash flow statement	6,189	5,488	5,430
Other Operations
Disclosure of operating segments [Line Items]
Capital expenditure	2	(4)	12
Product group
Disclosure of operating segments [Line Items]
Capital expenditure	6,320	5,831	5,279
Other items
Disclosure of operating segments [Line Items]
Capital expenditure	79	64	65
Capital expenditure of equity accounted units
Disclosure of operating segments [Line Items]
Capital expenditure	(255)	(456)	(500)
Operating segments | Reportable segments
Disclosure of operating segments [Line Items]
Capital expenditure	6,318	5,835	5,267
Operating segments | Iron Ore
Disclosure of operating segments [Line Items]
Capital expenditure	2,941	1,741	1,302
Operating segments | Aluminium
Disclosure of operating segments [Line Items]
Capital expenditure	1,085	1,456	1,373
Operating segments | Copper & Diamonds
Disclosure of operating segments [Line Items]
Capital expenditure	1,864	2,087	2,150
Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Capital expenditure	$ 428	$ 551	442
Kitimat
Disclosure of operating segments [Line Items]
Sales of property, plant and equipment and intangible assets			$ 508

Operating segments - Summary _3

Operating segments - Summary of depreciation and amortisation within the reportable segments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [Line Items]
Depreciation and amortisation expense proportionately consolidated	$ 4,279	$ 4,384	$ 4,015
Other Operations
Disclosure of operating segments [Line Items]
Depreciation and amortisation expense proportionately consolidated	199	177	26
Product group
Disclosure of operating segments [Line Items]
Depreciation and amortisation expense proportionately consolidated	4,773	4,960	4,622
Other items
Disclosure of operating segments [Line Items]
Depreciation and amortisation expense proportionately consolidated	82	77	43
Depreciation and amortisation of equity accounted units
Disclosure of operating segments [Line Items]
Depreciation and amortisation expense proportionately consolidated	(576)	(653)	(650)
Operating segments | Reportable segments
Disclosure of operating segments [Line Items]
Depreciation and amortisation expense proportionately consolidated	4,574	4,783	4,596
Operating segments | Iron Ore
Disclosure of operating segments [Line Items]
Depreciation and amortisation expense proportionately consolidated	1,838	1,723	1,702
Operating segments | Aluminium
Disclosure of operating segments [Line Items]
Depreciation and amortisation expense proportionately consolidated	1,191	1,312	1,122
Operating segments | Copper & Diamonds
Disclosure of operating segments [Line Items]
Depreciation and amortisation expense proportionately consolidated	1,153	1,320	1,317
Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Depreciation and amortisation expense proportionately consolidated	$ 392	$ 428	$ 455

Operating segments - Summary _4

Operating segments - Summary of tax charge within the reportable segments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [Line Items]
Tax expense (income)	$ 4,991	$ 4,147	$ 4,242
Other Operations
Disclosure of operating segments [Line Items]
Tax expense (income)	(7)	(51)	(51)
Product group
Disclosure of operating segments [Line Items]
Tax expense (income)	5,446	4,832	3,929
Other items
Disclosure of operating segments [Line Items]
Tax expense (income)	(179)	(67)	(276)
Exploration and evaluation not attributed to product groups
Disclosure of operating segments [Line Items]
Tax expense (income)	(34)	(83)	(38)
Net finance costs
Disclosure of operating segments [Line Items]
Tax expense (income)	(38)	(144)	(174)
Underlying EBITDA/earnings
Disclosure of operating segments [Line Items]
Tax expense (income)	5,195	4,538	3,441
Tax (credit)/charge excluded from underlying earnings
Disclosure of operating segments [Line Items]
Tax expense (income)	(204)	(391)	801
Operating segments | Reportable segments
Disclosure of operating segments [Line Items]
Tax expense (income)	5,477	4,885	3,980
Operating segments | Iron Ore
Disclosure of operating segments [Line Items]
Tax expense (income)	5,035	4,198	2,830
Operating segments | Aluminium
Disclosure of operating segments [Line Items]
Tax expense (income)	320	211	532
Operating segments | Copper & Diamonds
Disclosure of operating segments [Line Items]
Tax expense (income)	(238)	65	118
Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Tax expense (income)	360	411	500
Inter-segment transactions
Disclosure of operating segments [Line Items]
Tax expense (income)	$ (24)	$ (2)	$ 0

Operating segments - Summary _5

Operating segments - Summary of Underlying EBITDA (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [Line Items]
Underlying EBITDA	$ 23,902	$ 21,197	$ 18,136
Impairment charges	(1,272)	(3,487)	(132)
(Gains)/losses on embedded commodity derivatives not qualifying for hedge accounting (including exchange)	6	(260)	279
Net (losses)/gains on consolidation and disposal of interests in businesses	0	(291)	4,622
Change in closure estimates (non-operating and fully impaired sites)	(401)	0	(376)
Gain on sale of wharf and land in Kitimat, Canada	0	0	602
Change in other exclusions	0	(171)	0
Items excluded from underlying EBITDA	(1,667)	(4,209)	4,995
Depreciation and amortisation in subsidiaries and equity accounted units	(4,650)	(4,925)	(4,559)
Taxation and finance items in equity accounted units	(443)	(296)	(372)
Finance items	(1,751)	(648)	(33)
Profit before taxation	15,391	11,119	18,167
Other Operations
Disclosure of operating segments [Line Items]
Underlying EBITDA	0	(77)	(70)
Product group
Disclosure of operating segments [Line Items]
Underlying EBITDA	24,713	22,132	19,319
Central pension costs, share-based payments and insurance
Disclosure of operating segments [Line Items]
Underlying EBITDA	72	59	(128)
Restructuring, project and one-off costs
Disclosure of operating segments [Line Items]
Underlying EBITDA	(133)	(183)	(272)
Central costs
Disclosure of operating segments [Line Items]
Underlying EBITDA	(500)	(496)	(552)
Exploration and evaluation not attributed to product groups
Disclosure of operating segments [Line Items]
Underlying EBITDA	(250)	(315)	(231)
Operating segments | Reportable segments
Disclosure of operating segments [Line Items]
Underlying EBITDA	24,807	22,218	19,389
Operating segments | Iron Ore
Disclosure of operating segments [Line Items]
Underlying EBITDA	18,837	16,098	11,378
Operating segments | Aluminium
Disclosure of operating segments [Line Items]
Underlying EBITDA	2,152	2,285	3,095
Operating segments | Copper & Diamonds
Disclosure of operating segments [Line Items]
Underlying EBITDA	2,172	2,073	2,776
Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Underlying EBITDA	1,646	1,762	2,140
Inter-segment transactions
Disclosure of operating segments [Line Items]
Underlying EBITDA	$ (94)	$ (9)	$ 0

Operating segments - Summary _6

Operating segments - Summary of underlying earnings within the reportable segments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [Line Items]
Underlying earnings	$ 12,448	$ 10,373	$ 8,808
Profit/(loss) after tax – attributable to owners of Rio Tinto	9,769	8,010	13,638
Items excluded from underlying earnings	(2,679)	(2,363)	4,830
Other Operations
Disclosure of operating segments [Line Items]
Underlying earnings	(54)	(89)	(102)
Profit/(loss) after tax – attributable to owners of Rio Tinto	(54)	(89)	(102)
Product group
Disclosure of operating segments [Line Items]
Underlying earnings	13,123	11,310	9,825
Profit/(loss) after tax – attributable to owners of Rio Tinto	13,123	11,310	9,825
Central pension costs, share-based payments and insurance
Disclosure of operating segments [Line Items]
Profit/(loss) after tax – attributable to owners of Rio Tinto	81	60	(90)
Restructuring, project and one-off costs
Disclosure of operating segments [Line Items]
Profit/(loss) after tax – attributable to owners of Rio Tinto	(108)	(94)	(190)
Central costs
Disclosure of operating segments [Line Items]
Profit/(loss) after tax – attributable to owners of Rio Tinto	(418)	(550)	(410)
Exploration and evaluation not attributed to product groups
Disclosure of operating segments [Line Items]
Profit/(loss) after tax – attributable to owners of Rio Tinto	(216)	(231)	(193)
Net finance costs
Disclosure of operating segments [Line Items]
Profit/(loss) after tax – attributable to owners of Rio Tinto	(14)	(122)	(134)
Underlying EBITDA/earnings
Disclosure of operating segments [Line Items]
Profit/(loss) after tax – attributable to owners of Rio Tinto	12,448	10,373	8,808
Operating segments | Reportable segments
Disclosure of operating segments [Line Items]
Underlying earnings	13,209	11,402	9,927
Operating segments | Iron Ore
Disclosure of operating segments [Line Items]
Underlying earnings	11,398	9,638	6,531
Profit/(loss) after tax – attributable to owners of Rio Tinto	11,398	9,638	6,531
Operating segments | Aluminium
Disclosure of operating segments [Line Items]
Underlying earnings	471	599	1,347
Profit/(loss) after tax – attributable to owners of Rio Tinto	471	599	1,347
Operating segments | Copper & Diamonds
Disclosure of operating segments [Line Items]
Underlying earnings	763	554	1,054
Profit/(loss) after tax – attributable to owners of Rio Tinto	763	554	1,054
Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Underlying earnings	577	611	995
Profit/(loss) after tax – attributable to owners of Rio Tinto	577	611	995
Inter-segment transactions
Disclosure of operating segments [Line Items]
Underlying earnings	(32)	(3)	0
Profit/(loss) after tax – attributable to owners of Rio Tinto	$ (32)	$ (3)	$ 0

Operating segments - Reconcilia

Operating segments - Reconciliation of net earnings/(losses) to underlying earnings (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Exchange and Derivative Gains (Losses), Pre-Tax [Abstract]
Underlying Earnings Before Tax	$ 18,282
Impairment charges, pre tax	(1,243)	$ (3,487)	$ (132)
Net gains on consolidation and disposal of interests in businesses, Pre-tax	0
– Exchange (losses)/gains on external US dollar net debt and intragroup balances and derivatives, Pre-tax	(1,138)
Gain/(losses) on currency and interest rate derivatives not qualifying for hedge accounting, Pre-tax	(142)
(Losses)/gains on embedded commodity derivatives not qualifying for hedge accounting, Pre-tax	33
Net losses from movements to closure estimates (non-operating and fully impaired sites), Pre-tax	(401)
Other Exclusions From Underlying Earnings Before Tax	0
Items Excluded From Underlying Earnings Before Tax	(2,891)
Profit before taxation	15,391	11,119	18,167
Exchange And Derivative Gains Losses Tax [Abstract]
Underlying Earnings Tax	(5,195)
Impairment charges, Tax	128
Net gains on consolidation and disposal of interests in businesses, Tax	0
– Exchange (losses)/gains on external US dollar net debt and intragroup balances and derivatives, Tax	5
- Gain/(losses) on currency and interest rate derivatives not qualifying for hedge accounting, Tax	(19)
- (Losses)/gains on embedded commodity derivatives not qualifying for hedge accounting, Tax	(10)
Net losses from movements to closure estimates (non-operating and fully impaired sites), Tax	100
Tax Effect Of Other Exclusions	0
Total excluded from underlying earnings, Tax	204
Taxation	(4,991)	(4,147)	(4,242)
Exchange and derivative gains/(losses, Non-controlling interests
Underlying Earnings Attributable To Noncontrolling Interests	(639)
Impairment charges, Non-controlling interests	0	1,506	3
Net gains on consolidation and disposal of interests in businesses, Non-controlling interests	0
– Exchange (losses)/gains on external US dollar net debt and intragroup balances and drivatives, Non-controlling interests	8
– (Losses)/gains on currency and interest rate derivatives not qualifying for hedge accounting	4
– Gains/(losses) on embedded commodity derivatives not qualifying for hedge accounting	(5)
Net losses from movements to closure estimates (non-operating and fully impaired sites), Non-controlling interests	1
Other Exclusions From Underlying Earnings, Attributable to Noncontrolling interests	0
Total excluded from underlying earnings, Non-controlling interests	8
Profit after tax for the year – attributable to non-controlling interests	(631)	1,038	(287)
Exchange and derivative gains/(losses), Net
Underlying earnings, Net	12,448	10,373	8,808
Impairment charge, net amount	(1,115)	(1,658)	(104)
Net gains on consolidation and disposal of interests in businesses, Net	0	(291)	3,996
– Exchange (losses)/gains on external US dollar net debt and intragroup balances and derivatives, Net	(1,125)	51	550
– (Losses)/gains on currency and interest rate derivatives not qualifying for hedge accounting	(157)	(59)	(48)
– Gains/(losses) on embedded commodity derivatives not qualifying for hedge accounting	18	(192)	202
Net losses from movements to closure estimates (non-operating and fully impaired sites)	(300)	0	(335)
Gain relating to surplus land at Kitimat	0	0	569
Other Exclusions From Underlying Earnings Net	0	(214)	0
Total excluded from underlying earnings, Net	(2,679)	(2,363)	4,830
Net earnings – attributable to owners of Rio Tinto	$ 9,769	$ 8,010	$ 13,638

Operating segments - Reconcil_2

Operating segments - Reconciliation of net earnings/(losses) to underlying earnings (Parenthetical) (Detail) - USD ($) $ in Millions	Jul. 16, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [Line Items]
Profit before taxation		$ 15,391	$ 11,119	$ 18,167
Profit after tax for the year		10,400	6,972	13,925
Post-tax foreign exchange gains		1,330	9
Post-tax foreign exchange loss		$ 205	60
Closure discount rate		1.50%
US Dollar Net Debt
Disclosure of operating segments [Line Items]
Post-tax foreign exchange gains				386
Intragroup balances
Disclosure of operating segments [Line Items]
Post-tax foreign exchange loss				$ 936
Rossing Uranium Limited
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary	68.62%
Profit before taxation	$ 289
Profit after tax for the year	$ 289
Oyu Tolgoi
Disclosure of operating segments [Line Items]
Write-back of net realisable value provision			75
Impairment gain (loss) excluded from underlying earnings			19
Gove Refinery
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary		100.00%
Profit before taxation		$ 138
Obligations On Legacy Operations
Disclosure of operating segments [Line Items]
Write-back of net realisable value provision			246
Impairment gain (loss) excluded from underlying earnings			$ (233)

Operating segments - Addition_3

Operating segments - Additional information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [Line Items]
Percentage of capital expenditure	100.00%
Percentage of depreciation and amortisation	100.00%
Share of profit after tax of equity accounted units	$ 652	$ 301	$ 513
Gove Refinery
Disclosure of operating segments [Line Items]
Group interest (%)	100.00%
Copper & Diamonds
Disclosure of operating segments [Line Items]
Share of profit after tax of equity accounted units	$ 640	292	476
Other Operations
Disclosure of operating segments [Line Items]
Share of profit after tax of equity accounted units	16	10	37
Gross product sales
Disclosure of operating segments [Line Items]
Share of sales revenue of equity accounted units	2,441	2,234	2,354
Capital expenditure of equity accounted units
Disclosure of operating segments [Line Items]
Share of profit after tax of equity accounted units	656	302	513
Subsidiaries
Disclosure of operating segments [Line Items]
Share of sales revenue of equity accounted units	$ 34	$ 32	$ 41

Operating segments - addition_4

Operating segments - additional information - Consolidated sales revenue by destination (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of geographical areas [line items]
Percentage of consolidated sales revenue	100.00%	100.00%	100.00%
Consolidated sales revenue	$ 44,611	$ 43,165	$ 40,522
China
Disclosure of geographical areas [line items]
Percentage of consolidated sales revenue	58.10%	51.30%	44.60%
Consolidated sales revenue	$ 25,940	$ 22,135	$ 18,061
Asia (excluding China and Japan)
Disclosure of geographical areas [line items]
Percentage of consolidated sales revenue	10.20%	10.60%	11.50%
Consolidated sales revenue	$ 4,536	$ 4,558	$ 4,665
United States of America
Disclosure of geographical areas [line items]
Percentage of consolidated sales revenue	10.90%	14.20%	15.60%
Consolidated sales revenue	$ 4,867	$ 6,125	$ 6,337
Japan
Disclosure of geographical areas [line items]
Percentage of consolidated sales revenue	7.50%	8.90%	9.60%
Consolidated sales revenue	$ 3,354	$ 3,855	$ 3,873
Europe (excluding UK)
Disclosure of geographical areas [line items]
Percentage of consolidated sales revenue	5.90%	6.00%	9.30%
Consolidated sales revenue	$ 2,623	$ 2,610	$ 3,788
Canada
Disclosure of geographical areas [line items]
Percentage of consolidated sales revenue	2.90%	3.30%	3.30%
Consolidated sales revenue	$ 1,289	$ 1,478	$ 1,330
Australia
Disclosure of geographical areas [line items]
Percentage of consolidated sales revenue	1.70%	1.70%	1.80%
Consolidated sales revenue	$ 745	$ 737	$ 720
UK
Disclosure of geographical areas [line items]
Percentage of consolidated sales revenue	0.50%	0.60%	0.70%
Consolidated sales revenue	$ 242	$ 248	$ 264
Other countries
Disclosure of geographical areas [line items]
Percentage of consolidated sales revenue	2.30%	3.40%	3.60%
Consolidated sales revenue	$ 1,015	$ 1,419	$ 1,484

Operating segments - addition_5

Operating segments - additional information - Consolidated sales revenue by product (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of products and services [line items]
Revenue from contracts with customers	$ 43,492	$ 42,987	$ 40,594
Other revenue	1,119	178	(72)
Consolidated sales revenue	44,611	43,165	40,522
Share of equity accounted unit sales and intra-subsidiary/equity accounted unit sales
Disclosure of products and services [line items]
Share of equity accounted unit sales and intra-subsidiary/equity accounted unit sales	2,407	2,202	2,313
Gross product sales
Disclosure of products and services [line items]
Consolidated sales revenue	47,018	45,367	42,835
Iron Ore
Disclosure of products and services [line items]
Revenue from contracts with customers	28,202	25,516	19,888
Other revenue	1,000	229	(21)
Consolidated sales revenue	29,202	25,745	19,867
Aluminium, Alumina and Bauxite
Disclosure of products and services [line items]
Revenue from contracts with customers	9,092	10,207	12,041
Other revenue	54	(32)	(22)
Consolidated sales revenue	9,146	10,175	12,019
Copper
Disclosure of products and services [line items]
Revenue from contracts with customers	1,721	2,030	2,420
Other revenue	64	(7)	(32)
Consolidated sales revenue	1,785	2,023	2,388
Coal
Disclosure of products and services [line items]
Revenue from contracts with customers		0	986
Other revenue		0	3
Consolidated sales revenue		0	989
Industrial minerals
Disclosure of products and services [line items]
Revenue from contracts with customers	2,054	2,251	2,168
Other revenue	(3)	(12)	0
Consolidated sales revenue	2,051	2,239	2,168
Gold
Disclosure of products and services [line items]
Revenue from contracts with customers	471	667	869
Other revenue	6	2	0
Consolidated sales revenue	477	669	869
Diamonds
Disclosure of products and services [line items]
Revenue from contracts with customers	459	619	695
Other revenue	0	0	0
Consolidated sales revenue	459	619	695
Uranium
Disclosure of products and services [line items]
Revenue from contracts with customers	299	375	415
Other revenue	0	0	0
Consolidated sales revenue	299	375	415
Other
Disclosure of products and services [line items]
Revenue from contracts with customers	1,194	1,322	1,112
Other revenue	(2)	(2)	0
Consolidated sales revenue	$ 1,192	$ 1,320	$ 1,112

Operating segments - addition_6

Operating segments - additional information - Summary of non-current assets other than excluded items (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of geographical areas [line items]
Non-current assets other than excluded items	$ 70,680	$ 65,198
Deferred tax assets	3,385	3,102
Other financial assets	829	635
Loans to equity accounted units	112	113
Tax recoverable	4	5
Receivables and other assets	1,525	1,446
Total non-current assets	76,535	70,499
Non-current assets
Disclosure of geographical areas [line items]
Investments in equity accounted units	3,652	3,858
Quasi equity loans to equity accounted units
Disclosure of geographical areas [line items]
Loans to equity accounted units	112	113
Non-quasi equity loan
Disclosure of geographical areas [line items]
Non-current quasi equity loans	1	39
Australia
Disclosure of geographical areas [line items]
Non-current assets other than excluded items	32,290	27,944
Deferred tax assets	649	698
Canada
Disclosure of geographical areas [line items]
Non-current assets other than excluded items	14,666	14,644
Deferred tax assets	617	492
Mongolia
Disclosure of geographical areas [line items]
Non-current assets other than excluded items	10,285	9,187
Deferred tax assets	974	704
United States of America
Disclosure of geographical areas [line items]
Non-current assets other than excluded items	6,090	5,459
Deferred tax assets	938	920
Africa
Disclosure of geographical areas [line items]
Non-current assets other than excluded items	3,294	3,583
South America
Disclosure of geographical areas [line items]
Non-current assets other than excluded items	2,718	2,652
Europe (excluding France and the UK)
Disclosure of geographical areas [line items]
Non-current assets other than excluded items	157	193
UK
Disclosure of geographical areas [line items]
Non-current assets other than excluded items	117	158
France
Disclosure of geographical areas [line items]
Non-current assets other than excluded items	55	64
Deferred tax assets	0	0
Other countries
Disclosure of geographical areas [line items]
Non-current assets other than excluded items	1,008	1,314
Deferred tax assets	$ 207	$ 288

Net operating costs (excludin_3

Net operating costs (excluding items shown separately) - Summary of net operating costs (excluding items shown separately) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Expenses by nature [abstract]
Raw materials, consumables, repairs and maintenance	$ 8,490	$ 9,485	$ 10,613
Amortisation of intangible assets	161	133	133
Depreciation of property, plant and equipment	4,118	4,251	3,882
Employment costs	4,770	4,522	4,728
Shipping and other freight costs	2,088	2,257	2,580
(Increase)/decrease in finished goods and work in progress	(47)	42	(186)
Royalties	2,763	2,501	2,117
Amounts charged by equity accounted units	958	1,136	1,200
Net foreign exchange losses/(gains)	300	(52)	(56)
Other external costs	3,083	3,627	3,184
Gains on sale of property, plant and equipment	50	31	(506)
Provisions (including exchange differences on provisions)	894	753	1,011
Research and development	45	45	45
Costs included above capitalised or shown separately as exploration and evaluation costs	(708)	(651)	(589)
Other operating income	(711)	(773)	(1,041)
Net operating costs (excluding items shown separately)	$ 26,254	$ 27,307	$ 27,115

Net operating costs (excludin_4

Net operating costs (excluding items shown separately) - Summary of net operating costs (excluding items shown separately) Footnotes (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Operating Costs [Line Items]
Short-term lease costs	$ 314	$ 327
Payments for variable lease components	30	15
Operating lease expenses			$ 787
Purchases of the other investors' share of production	129	291	332
Pre-tax gains on disposals of property, plant and equipment	45	49	586
Operating costs capitalised	537	469	400
Exploration and evaluation costs	$ 171	$ 182	189
Kitimat
Disclosure Of Operating Costs [Line Items]
Pre-tax gains on disposals of property, plant and equipment			$ 549

Employment costs - Summary of e

Employment costs - Summary of employment costs (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Total employment costs
– Wages and salaries	$ 4,141	$ 3,923	$ 4,154
– Social security costs	330	328	336
– Net post-retirement charge	469	384	532
– Share-based payment charge	138	123	122
Employment costs before utilisation of provisions	5,078	4,758	5,144
Less: charged within provisions	(308)	(236)	(416)
Total employment costs	$ 4,770	$ 4,522	$ 4,728

Impairment charges - Summary of

Impairment charges - Summary of impairment charges (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Total impairment charge		$ (1,243)	$ (3,487)	$ (132)
Impairment charges, Tax		128
Impairment charges, Non-controlling interests		0	1,506	3
Impairment charge, net amount		(1,115)	(1,658)	(104)
Impairment loss recognised in profit or loss		904	3,487	132
Impairment charges related to EAUs (pre-tax)		(368)	0	0
Impairment charges		(1,272)	(3,487)	(132)
Taxation (including related to EAUs)		157	323	25
Intangible assets
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Total impairment charge		(4)	(1)	(2)
Property, plant and equipment
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Total impairment charge		(900)	(3,486)	(130)
Investment in equity accounted units ("EAUs")
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Total impairment charge			0	0
Aluminium | Pacific Aluminium
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Total impairment charge		(489)	0
Impairment charges, Tax		17
Impairment charges, Non-controlling interests		0
Impairment charge, net amount		(472)
Aluminium | Pacific Aluminium | Investment in equity accounted units ("EAUs")
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Total impairment charge		(339)
Aluminium | Sohar
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Total impairment charge		(220)	0	0
Impairment charges, Tax		0
Impairment charges, Non-controlling interests		0
Impairment charge, net amount		(220)
Aluminium | Sohar | Investment in equity accounted units ("EAUs")
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment loss recognised in profit or loss	$ 220
Aluminium | ISAL
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Total impairment charge		(93)	(109)	(123)
Impairment charges, Tax		(38)
Impairment charges, Non-controlling interests		0
Impairment charge, net amount		(131)
Aluminium | Yarwun Alumina Refinery
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Total impairment charge		0	(1,138)	0
Impairment charges, Tax		0
Impairment charges, Non-controlling interests		0
Impairment charge, net amount		0
Impairment loss recognised in profit or loss			1,138
Copper & Diamonds | Diavik
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Total impairment charge		(441)	0
Impairment charges, Tax		149
Impairment charges, Non-controlling interests		0
Impairment charge, net amount		(292)
Copper & Diamonds | Oyu Tolgoi
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Total impairment charge		0	(2,240)	0
Impairment charges, Tax		0
Impairment charges, Non-controlling interests		0
Impairment charge, net amount		0
Energy & Minerals | Rossing
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Total impairment charge		0	$ 0	$ (9)
Impairment charges, Tax		0
Impairment charges, Non-controlling interests		0
Impairment charge, net amount		$ 0

Impairment charges - Additional

Impairment charges - Additional information (Detail) - USD ($) $ in Millions		Dec. 16, 2020	Jul. 09, 2020	Jul. 16, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of impairment loss and reversal of impairment loss [line items]
Impairment loss recognised in profit or loss								$ 904	$ 3,487	$ 132
Cash flows from consolidated operations	[1]							21,822	19,705	15,655
Pacific Aluminium
Disclosure of impairment loss and reversal of impairment loss [line items]
Contract termination notice period			14 months
Pacific Aluminium | Aluminium
Disclosure of impairment loss and reversal of impairment loss [line items]
Recoverable amount of asset or cash-generating unit								$ 273
Discount rate applied to cash flow projections								6.60%
Pre-tax impairment charge net of reversals								$ (26)
Pacific Aluminium | Aluminium | Pre Tax
Disclosure of impairment loss and reversal of impairment loss [line items]
Pre-tax impairment charge net of reversals								(36)
Pacific Aluminum Smelter | Aluminium
Disclosure of impairment loss and reversal of impairment loss [line items]
Pre-tax impairment charge net of reversals								(119)
Pacific Aluminum Smelter | Aluminium | Pre Tax
Disclosure of impairment loss and reversal of impairment loss [line items]
Pre-tax impairment charge net of reversals								(148)
Sohar | Aluminium
Disclosure of impairment loss and reversal of impairment loss [line items]
Recoverable amount of asset or cash-generating unit							$ 258
Discount rate applied to cash flow projections							7.60%
Sohar | Aluminium | Investment in equity accounted units ("EAUs")
Disclosure of impairment loss and reversal of impairment loss [line items]
Impairment loss recognised in profit or loss							$ 220
ISAL | Aluminium
Disclosure of impairment loss and reversal of impairment loss [line items]
Recoverable amount of asset or cash-generating unit								$ 139	$ 302
Discount rate applied to cash flow projections								6.60%	6.90%
Pre-tax impairment charge net of reversals					$ (204)				$ (109)	123
Reversal of impairment loss recognised in profit or loss								$ 111
ISAL | Alufluor Ab | Aluminium
Disclosure of impairment loss and reversal of impairment loss [line items]
Recoverable amount of asset or cash-generating unit									46
ISAL | Assets and liabilities classified as held for sale
Disclosure of impairment loss and reversal of impairment loss [line items]
Business acquisition binding offer amount										$ 345
ISAL | Assets and liabilities classified as held for sale | Aluminerie Alouette Inc. | Netherlands
Disclosure of impairment loss and reversal of impairment loss [line items]
Percentage of ownership interest to be sold										53.30%
ISAL | Assets and liabilities classified as held for sale | Alufluor Ab | Sweden
Disclosure of impairment loss and reversal of impairment loss [line items]
Percentage of ownership interest to be sold										50.00%
Diavik | Copper & Diamonds
Disclosure of impairment loss and reversal of impairment loss [line items]
Proportion of ownership interest in joint venture								40.00%
Oyu Tolgoi | Copper & Diamonds
Disclosure of impairment loss and reversal of impairment loss [line items]
Recoverable amount of asset or cash-generating unit						$ 8,300
Discount rate applied to cash flow projections					8.30%
Property development and project management expense		$ 6,750		$ 5,300
Recoverable amount of asset or cash generating unit, percent					20.00%
Deferred tax expense (income) relating to origination and reversal of temporary differences						320
Deductible temporary differences for which no deferred tax asset is recognised						359
Carrying amount of asset or cash-generating unit								$ 10,100
Cash flows from consolidated operations								$ 1,100
Oyu Tolgoi | Copper & Diamonds | Pre Tax
Disclosure of impairment loss and reversal of impairment loss [line items]
Pre-tax impairment charge net of reversals						$ (2,200)
Yarwun Alumina Refinery | Aluminium
Disclosure of impairment loss and reversal of impairment loss [line items]
Impairment loss recognised in profit or loss									$ 1,138
Impairment loss, annual reduction, percent									30.00%
Bottom of range | Oyu Tolgoi | Copper & Diamonds
Disclosure of impairment loss and reversal of impairment loss [line items]
Production delay period				16 months
Property development and project management expense, estimated increase				$ 1,200
Top of range | Oyu Tolgoi | Copper & Diamonds
Disclosure of impairment loss and reversal of impairment loss [line items]
Production delay period				30 months
Property development and project management expense, estimated increase				$ 1,900
[1]	(a) Cash flows from consolidated operations Profit after tax for the year 10,400 6,972 13,925 Adjustments for: – Taxation 4,991 4,147 4,242 – Finance items 1,751 648 33 – Share of profit after tax of equity accounted units (652) (301) (513) – Net losses/(gains) on consolidation and disposal of interests in businesses 36 — 291 (4,622) – Impairment charges of investments in equity accounted units after tax 6 339 — — – Impairment charges 6 904 3,487 132 – Depreciation and amortisation 4,279 4,384 4,015 – Provisions (including exchange differences on provisions) 894 753 1,011 Utilisation of provisions (582) (539) (620) Utilisation of provision for post-retirement benefits 25 (192) (205) (219) Change in inventories (281) 28 (587) Change in receivables and other assets (562) 163 (421) Change in trade and other payables 558 (191) 476 Other items (d) (25) 68 (1,197) 21,822 19,705 15,655

Share of profit after tax of _3

Share of profit after tax of equity accounted units - Summary of share of profit after tax of equity accounted units (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Equity Accounted Units [Line Items]
Sales revenue: Rio Tinto share	$ 44,611	$ 43,165	$ 40,522
Operating costs	(26,254)	(27,307)	(27,115)
Finance items	(1,751)	(648)	(33)
Profit before taxation	15,391	11,119	18,167
Taxation	(4,991)	(4,147)	(4,242)
Rio Tinto
Disclosure Of Equity Accounted Units [Line Items]
Sales revenue: Rio Tinto share	2,490	2,358	2,497
Operating costs	(1,439)	(1,812)	(1,656)
Profit before finance items and taxation	1,051	546	841
Finance items	(59)	(65)	(69)
Share of profit after tax of equity accounted units	23	10	14
Profit before taxation	1,015	491	786
Taxation	(363)	(190)	(273)
Profit for the year (Rio Tinto share)	$ 652	$ 301	$ 513

Finance income and finance co_3

Finance income and finance costs - Summary of finance income and finance costs (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Finance Income Expense Explanatory [Abstract]
Finance income from equity accounted units	$ 4	$ 4	$ 7
Other finance income (including bank deposits, net investment in leases, and other financial assets)	137	296	242
Total finance income	141	300	249
Interest on:
Financial liabilities at amortised cost (excluding lease liabilities) and associated derivatives	(561)	(816)	(775)
Lease liabilities	(50)	(55)	(2)
Fair value movements:
Bonds designated as hedged items in fair value hedges	(284)	(185)	96
Derivatives designated as hedging instruments in fair value hedges	287	181	(73)
Loss on early redemption of bonds	0	0	(94)
Amounts capitalised	340	321	296
Total finance costs	$ (268)	$ (554)	$ (552)

Finance income and finance co_4

Finance income and finance costs - Summary of finance income and finance costs (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of borrowings and other financial liabilities [Line Items]
Buy-back of bonds			$ 1,900
Premium charges for redemption of bonds			72
Unamortized debt issuance costs and fees			9
Fair value hedge adjustment			16
Net interest paid associated with bond redepemption			80
Cost of hedging reserve
Disclosure of borrowings and other financial liabilities [Line Items]
Transfer of cost of hedging to the income statement	$ 0	$ 0	$ (3)

Taxation - Summary of taxation

Taxation - Summary of taxation charge (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Major components of tax expense (income) [abstract]
– Current	$ 5,169	$ 4,436	$ 3,726
– Deferred	(178)	(289)	516
Total taxation charge	$ 4,991	$ 4,147	$ 4,242

Taxation - Summary of prima fac

Taxation - Summary of prima facie tax reconciliation (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of accounting profit multiplied by applicable tax rates [abstract]
Applicable tax rate	19.00%	19.00%	19.00%
Profit before taxation	$ 15,391	$ 11,119	$ 18,167
Deduct: share of profit after tax of equity accounted units	(652)	(301)	(513)
Impairment after tax of investment in equity accounted unit	339	0	0
Parent companies' and subsidiaries' profit before tax	15,078	10,818	17,654
Prima facie tax payable at UK rate of 19% (2019: 19%; 2018: 19%)	2,865	2,055	3,354
Higher rate of taxation on Australian underlying earnings	1,779	1,495	1,106
Impact of items excluded in arriving at underlying earnings
– Impairment charges	44	340	0
– Net gains and losses on consolidation and disposal of interests in businesses	0	55	(251)
– Exchange and gains/losses on derivatives	260	(22)	32
– Losses from increases to closure estimates (non-operating and fully impaired sites)	(24)	0	30
– Gain relating to surplus land at Kitimat	0	0	(81)
– Other exclusions	0	38	0
Impact of changes in tax rates and laws	0	1	47
Other tax rates applicable outside the UK and Australia on underlying earnings	(80)	(110)	(47)
Resource depletion and other depreciation allowances	(34)	(57)	(46)
Recognition of previously recognised deferred tax assets	(182)	0	0
Write-down of previously recognised deferred tax assets	173	42	13
Amounts under/(over) provided in prior years	9	83	(108)
Other items	181	227	193
Total taxation charge	$ 4,991	$ 4,147	$ 4,242

Taxation - Summary of prima f_2

Taxation - Summary of prima facie tax reconciliation (Footnotes) (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of accounting profit multiplied by applicable tax rates [abstract]
Groups share of profit of equity accounted units net of tax	$ (363,000,000)	$ (190,000,000)	$ (273,000,000)
Income tax credit on impairment of equity accounted units	$ 29,000,000	$ 0

Taxation - Summary of tax relat

Taxation - Summary of tax relating to components of other comprehensive income or loss (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income tax relating to components of other comprehensive income that will be reclassified to profit or loss [abstract]
Cash flow hedge fair value gains	$ 3	$ (6)	$ (54)
Tax credit/(charge) on actuarial gains and losses on post-retirement benefit plans	112	83	(271)
Tax relating to components of other comprehensive income/(loss) for the year	$ 115	$ 77	$ (325)

Taxation - Summary of tax rel_2

Taxation - Summary of tax relating to components of other comprehensive income or loss (Footnotes) (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income tax relating to components of other comprehensive income that will be reclassified to profit or loss [abstract]
Deferred tax credit (charge) included in other comprehensive income	$ 115,000,000	$ 77,000,000	$ (325,000,000)
Current tax charge included in other comprehensive income	$ 0	$ 0	$ 0

Earnings per ordinary share - S

Earnings per ordinary share - Summary of earnings (loss) per ordinary shares (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings per share [abstract]
Basic earnings per share attributable to ordinary shareholders of Rio Tinto	$ 9,769	$ 8,010	$ 13,638
Diluted earnings per share attributable to ordinary shareholders of Rio Tinto	$ 9,769	$ 8,010	$ 13,638
Basic earnings per share attributable to ordinary shareholders of Rio Tinto, Weighted average number of shares (in shares)	1,617.4	1,630.1	1,719.3
Diluted earnings per share attributable to ordinary shareholders of Rio Tinto, Weighted average number of shares (in shares)	1,628.6	1,642.1	1,731.7
Basic earnings per share (in usd per share)	$ 6.040	$ 4.914	$ 7.932
Diluted earnings per share (in usd per share)	$ 5.998	$ 4.878	$ 7.876

Earnings per ordinary share -_2

Earnings per ordinary share - Summary of earnings (loss) per ordinary shares (Footnotes) (Detail) - shares shares in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings per share [line items]
Weighted average number of shares outstanding (in shares)	1,617.4	1,630.1	1,719.3
Effect of dilutive securities shares	11.2	12	12.4
Rio Tinto plc
Earnings per share [line items]
Weighted average number of shares outstanding (in shares)	1,246.5	1,259.4	1,312.7
Rio Tinto Limited
Earnings per share [line items]
Weighted average number of shares outstanding (in shares)	370.9	370.7	406.6

Dividends - Summary of dividend

Dividends - Summary of dividends paid (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Dividends [Line Items]
Dividends paid during the year	$ 6,132	$ 10,334	$ 5,356
Dividends per share: paid during the year (in usd per share)	$ 3.860	$ 6.350	$ 3.070
Final Dividends
Disclosure of Dividends [Line Items]
Final dividends per share: proposed in the announcement of the results for the year (in usd per share)	3.090	2.310	1.800
Special Dividends
Disclosure of Dividends [Line Items]
Final dividends per share: proposed in the announcement of the results for the year (in usd per share)	$ 0.930	$ 0	$ 2.430
Rio Tinto plc | Final Dividends
Disclosure of Dividends [Line Items]
Previous year final dividend paid	$ 2,783	$ 2,245	$ 2,446
Interim dividend paid	1,937	1,930	1,666
Rio Tinto plc | Special Dividends
Disclosure of Dividends [Line Items]
Previous year final dividend paid	0	3,032	0
Interim dividend paid	0	780	0
Rio Tinto Limited | Final Dividends
Disclosure of Dividends [Line Items]
Previous year final dividend paid	857	666	731
Interim dividend paid	555	556	513
Rio Tinto Limited | Special Dividends
Disclosure of Dividends [Line Items]
Previous year final dividend paid	0	900	0
Interim dividend paid	$ 0	$ 225	$ 0

Dividends - Summary of divide_2

Dividends - Summary of dividends per share (Detail)	12 Months Ended
	Dec. 31, 2020£ / shares	Dec. 31, 2020$ / shares	Dec. 31, 2020$ / shares	Dec. 31, 2019£ / shares	Dec. 31, 2019$ / shares	Dec. 31, 2019$ / shares	Dec. 31, 2018£ / shares	Dec. 31, 2018$ / shares	Dec. 31, 2018$ / shares
Final Dividends | Rio Tinto plc
Disclosure of Dividends [Line Items]
Previous year final dividend per share (in pence per share) | (per share)	£ 1.7747	$ 2.310		£ 1.3596	$ 1.800		£ 1.2943	$ 1.800
Interim dividend per share (in usd per share) | (per share)	1.1974	$ 1.550		1.2332	1.510		0.9682	1.270
Final Dividends | Rio Tinto Limited
Disclosure of Dividends [Line Items]
Previous year final dividend per share (in pence per share)			$ 3.4974			$ 2.5089			$ 2.2853
Interim dividend per share (in usd per share)			2.1647			2.1908			1.7084
Special Dividends | Rio Tinto plc
Disclosure of Dividends [Line Items]
Previous year final dividend per share (in pence per share) | (per share)	0			1.8355	2.430			$ 0
Interim dividend per share (in usd per share) | (per share)	£ 0			£ 0.4982	$ 0.610		£ 0
Special Dividends | Rio Tinto Limited
Disclosure of Dividends [Line Items]
Previous year final dividend per share (in pence per share)			0			3.3870			0
Interim dividend per share (in usd per share)			$ 0			$ 0.8850			$ 0

Dividends - Summary of divide_3

Dividends - Summary of dividends per share (Parenthetical) (Detail) - Rio Tinto Limited	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Dividends [Line Items]
Franked final dividend percentage	30.00%	30.00%	30.00%
Franked Interim dividend percentage	30.00%	30.00%	30.00%

Dividends - Summary of number o

Dividends - Summary of number of shares dividend distributed (Detail) - shares shares in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Final Dividends | Rio Tinto plc
Disclosure of Dividends [Line Items]
Previous year final dividend number of shares (in shares)	1,246.4	1,265	1,334.8
Interim dividend number of shares (in shares)	1,246.5	1,256.4	1,308.4
Final Dividends | Rio Tinto Limited
Disclosure of Dividends [Line Items]
Previous year final dividend number of shares (in shares)	371.2	371.2	412.4
Interim dividend number of shares (in shares)	371.2	371.2	412.4
Special Dividends | Rio Tinto plc
Disclosure of Dividends [Line Items]
Previous year final dividend number of shares (in shares)		1,265
Interim dividend number of shares (in shares)		1,256.4
Special Dividends | Rio Tinto Limited
Disclosure of Dividends [Line Items]
Previous year final dividend number of shares (in shares)		371.2
Interim dividend number of shares (in shares)		371.2

Dividends - Additional informat

Dividends - Additional information (Detail) $ / shares in Units, $ in Millions	Feb. 17, 2021USD ($)$ / shares	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2020USD ($)£ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2019USD ($)£ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2018USD ($)£ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares
Disclosure of Dividends [Line Items]
Number of shares held (in shares) | shares		0	0	0	0	0	0	0	0	0
Final Dividends
Disclosure of Dividends [Line Items]
Final dividends per share: proposed in the announcement of the results for the year (in usd per share) | $ / shares		$ 3.090			$ 2.310			$ 1.800
Special Dividends
Disclosure of Dividends [Line Items]
Final dividends per share: proposed in the announcement of the results for the year (in usd per share) | $ / shares		0.930			0			2.430
Potential ordinary share transactions
Disclosure of Dividends [Line Items]
Final dividends per share: proposed in the announcement of the results for the year (in usd per share) | $ / shares	$ 3.090
Dividends payment proposed in the announcement of the results for the year | $	$ 6,500
Potential ordinary share transactions | Special Dividends
Disclosure of Dividends [Line Items]
Final dividends per share: proposed in the announcement of the results for the year (in usd per share) | $ / shares	$ 0.930
Rio Tinto plc | Final Dividends
Disclosure of Dividends [Line Items]
Final dividend per share (in usd per share) | (per share)		2.310	£ 1.7747		1.800	£ 1.3596		1.800	£ 1.2943
Interim dividend per share (in usd per share) | (per share)		$ 1.550	1.1974		1.510	1.2332		1.270	0.9682
Rio Tinto plc | Special Dividends
Disclosure of Dividends [Line Items]
Final dividend per share (in usd per share) | (per share)			0		2.430	1.8355		$ 0
Interim dividend per share (in usd per share) | (per share)			£ 0		$ 0.610	£ 0.4982			£ 0
Rio Tinto plc | Ordinary
Disclosure of Dividends [Line Items]
Number of share excluded from previous year final dividend calculation (in shares) | shares		258,779	258,779	258,779	852,283	852,283	852,283	132,294	132,294	132,294
Number of share excluded from interim dividend calculation (in shares) | shares		171,213	171,213	171,213	564,099	564,099	564,099	314,529	314,529	314,529
Rio Tinto plc | American depository receipts
Disclosure of Dividends [Line Items]
Number of share excluded from previous year final dividend calculation (in shares) | shares		28,743	28,743	28,743	37,678	37,678	37,678	22,824	22,824	22,824
Number of share excluded from interim dividend calculation (in shares) | shares		29,634	29,634	29,634	47,674	47,674	47,674	36,321	36,321	36,321
Rio Tinto Limited
Disclosure of Dividends [Line Items]
Number of share excluded from previous year final dividend calculation (in shares) | shares		98,065	98,065	98,065	628,566	628,566	628,566	130,129	130,129	130,129
Number of share excluded from interim dividend calculation (in shares) | shares		84,377	84,377	84,377	342,062	342,062	342,062	251,394	251,394	251,394
Number of shares held (in shares) | shares		828,338	828,338	828,338
Retained profits and reserves distributed as dividends | $		$ 11,014	£ 11,014	$ 11,014	$ 8,599	£ 8,599	$ 8,599	$ 6,178	£ 6,178	$ 6,178
Rio Tinto Limited | Final Dividends
Disclosure of Dividends [Line Items]
Final dividend per share (in usd per share) | $ / shares				$ 3.4974			$ 2.5089			$ 2.2853
Interim dividend per share (in usd per share) | $ / shares				2.1647			2.1908			1.7084
Rio Tinto Limited | Special Dividends
Disclosure of Dividends [Line Items]
Final dividend per share (in usd per share) | $ / shares				0			3.3870			0
Interim dividend per share (in usd per share) | $ / shares				$ 0			$ 0.8850			$ 0

Goodwill - Summary of goodwill

Goodwill - Summary of goodwill (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of reconciliation of changes in goodwill [Line Items]
Goodwill at beginning of period	$ 922	$ 912
Adjustment on currency translation	24	10
Goodwill at end of period	946	922
Cost
Disclosure of reconciliation of changes in goodwill [Line Items]
Goodwill at beginning of period	16,926	15,861
Goodwill at end of period	17,341	16,926
Accumulated impairment
Disclosure of reconciliation of changes in goodwill [Line Items]
Goodwill at beginning of period	(16,004)	(14,949)
Goodwill at end of period	$ (16,395)	$ (16,004)

Goodwill - Summary of Allocated

Goodwill - Summary of Allocated goodwill (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of reconciliation of changes in goodwill [Line Items]
Goodwill	$ 946	$ 922	$ 912
Richards Bay Minerals
Disclosure of reconciliation of changes in goodwill [Line Items]
Goodwill	468	487
Pilbara
Disclosure of reconciliation of changes in goodwill [Line Items]
Goodwill	383	349
Dampier Salt
Disclosure of reconciliation of changes in goodwill [Line Items]
Goodwill	$ 95	$ 86

Goodwill - Additional informati

Goodwill - Additional information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Richards Bay Minerals
Disclosure of reconciliation of changes in goodwill [Line Items]
Impairment charges	$ 0	$ 0
Fair value less costs of disposal, post-tax discount rate	8.60%	8.60%
Pilbara
Disclosure of reconciliation of changes in goodwill [Line Items]
Fair value less costs of disposal, post-tax discount rate	6.60%	6.60%

Goodwill - Key assumptions calc

Goodwill - Key assumptions calculation of fair value less costs of disposal (Detail) - Richards Bay Minerals $ in Millions	Dec. 31, 2020USD ($)
5% decrease in the titanium slag price
Disclosure of key assumptions calculation of fair value less costs of disposal [Line Items]
Corresponding decrease in FVLCD	$ 182
1% increase in the discount rate applied to post-tax cash flows
Disclosure of key assumptions calculation of fair value less costs of disposal [Line Items]
Corresponding decrease in FVLCD	213
10% strengthening of the South African rand
Disclosure of key assumptions calculation of fair value less costs of disposal [Line Items]
Corresponding decrease in FVLCD	$ 393

Goodwill - Key assumptions ca_2

Goodwill - Key assumptions calculation of fair value less costs of disposal (Parenthetical) (Detail) - Richards Bay Minerals	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of key assumptions calculation of fair value less costs of disposal [Line Items]
Fair value less costs of disposal, post-tax discount rate	8.60%	8.60%
5% decrease in the titanium slag price | Titanium
Disclosure of key assumptions calculation of fair value less costs of disposal [Line Items]
Percentage of decrease in the titanium slag price	5.00%
1% increase in the discount rate applied to post-tax cash flows
Disclosure of key assumptions calculation of fair value less costs of disposal [Line Items]
Fair value less costs of disposal, post-tax discount rate	1.00%
10% strengthening of the South African rand
Disclosure of key assumptions calculation of fair value less costs of disposal [Line Items]
Strengthening percentage of the South African rand	10.00%

Intangible assets - Summary of

Intangible assets - Summary of intangible assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	$ 2,637	$ 2,779
Adjustment on currency translation	111	71
Expenditure during the year	156	91
Amortisation for the year	(161)	(133)	$ (133)
Impairment charges	(4)	(1)
Disposals, transfers and other movements	16	(170)
Intangible assets at end of period	2,755	2,637	2,779
Cost
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	7,038
Intangible assets at end of period	7,427	7,038
Accumulated amortisation and impairment
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	(4,401)
Intangible assets at end of period	(4,672)	(4,401)
Exploration and evaluation
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	173	233
Adjustment on currency translation	17	(1)
Expenditure during the year	87	57
Amortisation for the year	0	0
Impairment charges	0	0
Disposals, transfers and other movements	(6)	(116)
Intangible assets at end of period	271	173	233
Exploration and evaluation | Cost
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	2,306
Intangible assets at end of period	2,415	2,306
Exploration and evaluation | Accumulated amortisation and impairment
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	(2,133)
Intangible assets at end of period	(2,144)	(2,133)
Trademarks, patented and non-patented technology
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	44	59
Adjustment on currency translation	3	(1)
Expenditure during the year	0	0
Amortisation for the year	(14)	(14)
Impairment charges	0	0
Disposals, transfers and other movements	0	0
Intangible assets at end of period	33	44	59
Trademarks, patented and non-patented technology | Cost
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	214
Intangible assets at end of period	232	214
Trademarks, patented and non-patented technology | Accumulated amortisation and impairment
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	(170)
Intangible assets at end of period	(199)	(170)
Contract based intangible assets
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	1,947	1,982
Adjustment on currency translation	56	74
Expenditure during the year	0	0
Amortisation for the year	(8)	(8)
Impairment charges	0	0
Disposals, transfers and other movements	(1)	(101)
Intangible assets at end of period	1,994	1,947	1,982
Contract based intangible assets | Cost
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	3,002
Intangible assets at end of period	3,070	3,002
Contract based intangible assets | Accumulated amortisation and impairment
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	(1,055)
Intangible assets at end of period	(1,076)	(1,055)
Other intangible assets
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	473	505
Adjustment on currency translation	35	(1)
Expenditure during the year	69	34
Amortisation for the year	(139)	(111)
Impairment charges	(4)	(1)
Disposals, transfers and other movements	23	47
Intangible assets at end of period	457	473	$ 505
Other intangible assets | Cost
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	1,516
Intangible assets at end of period	1,710	1,516
Other intangible assets | Accumulated amortisation and impairment
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets at beginning of period	(1,043)
Intangible assets at end of period	$ (1,253)	$ (1,043)

Intangible assets - Summary o_2

Intangible assets - Summary of intangible assets (Footnotes) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets	$ 2,755	$ 2,637	$ 2,779
Disposals, transfers and other movements	$ 16	$ (170)
Quebec smelters
Disclosure of detailed information about intangible assets [Line Items]
Fair value less costs of disposal, post-tax discount rate	6.60%	6.60%
Water rights | Quebec smelters
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets	$ 1,798	$ 1,759
Trademarks | Bottom of range
Disclosure of detailed information about intangible assets [Line Items]
Finite life intangible assets, useful lives	14
Trademarks | Top of range
Disclosure of detailed information about intangible assets [Line Items]
Finite life intangible assets, useful lives	20 years
Patented and non-patented technology | Bottom of range
Disclosure of detailed information about intangible assets [Line Items]
Finite life intangible assets, useful lives	ten
Patented and non-patented technology | Top of range
Disclosure of detailed information about intangible assets [Line Items]
Finite life intangible assets, useful lives	20 years
Power contracts water rights | Bottom of range
Disclosure of detailed information about intangible assets [Line Items]
Finite life intangible assets, useful lives	two
Power contracts water rights | Top of range
Disclosure of detailed information about intangible assets [Line Items]
Finite life intangible assets, useful lives	45 years
Other purchase and customer contracts | Bottom of range
Disclosure of detailed information about intangible assets [Line Items]
Finite life intangible assets, useful lives	five
Other purchase and customer contracts | Top of range
Disclosure of detailed information about intangible assets [Line Items]
Finite life intangible assets, useful lives	15 years
Computer software | Bottom of range
Disclosure of detailed information about intangible assets [Line Items]
Finite life intangible assets, useful lives	two
Computer software | Top of range
Disclosure of detailed information about intangible assets [Line Items]
Finite life intangible assets, useful lives	five years
Other intangible assets
Disclosure of detailed information about intangible assets [Line Items]
Intangible assets	$ 457	473	$ 505
Disposals, transfers and other movements	$ 23	$ 47
Other intangible assets | Bottom of range
Disclosure of detailed information about intangible assets [Line Items]
Finite life intangible assets, useful lives	two
Other intangible assets | Top of range
Disclosure of detailed information about intangible assets [Line Items]
Finite life intangible assets, useful lives	20 years

Intangible assets - Summary o_3

Intangible assets - Summary of exploration and evaluation expenditure (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Exploration And Evaluation Expenditure [Abstract]
Net expenditure in the year (net of cash proceeds of US$1 million (2019: US$10 million; 2018: US$233 million) on disposal of undeveloped projects)	$ (711)	$ (671)	$ (345)
Non-cash movements and non-cash proceeds on disposal of undeveloped projects	0	0	45
Exploration and evaluation costs capitalised	87	57	90
Net charge for the year	(624)	(614)	(210)
Reconciliation to income statement:
Exploration and evaluation costs	(625)	(624)	(488)
Profit/(loss) relating to interests in undeveloped projects	1	10	278
Net charge for the year	$ (624)	$ (614)	$ (210)

Intangible assets - Summary o_4

Intangible assets - Summary of exploration and evaluation expenditure (Parenthetical and Footnotes) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about intangible assets [Line Items]
Proceeds from disposal of exploration and evaluation assets	$ 1	$ 10	$ 233
Valeria
Disclosure of detailed information about intangible assets [Line Items]
Gain on sales of undeveloped properties			83
Winchester South
Disclosure of detailed information about intangible assets [Line Items]
Gain on sales of undeveloped properties			$ 195

Intangible assets - Additional

Intangible assets - Additional information (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Exploration and evaluation assets
Disclosure of detailed information about intangible assets [Line Items]
Capitalised related to projects which had not yet been approved to proceed	$ 271	$ 173

Property, plant and equipment P

Property, plant and equipment Property, plant and equipment - Summary of owned and leased assets (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Property, plant and equipment [abstract]
Property, plant and equipment – owned	$ 62,007	$ 56,307
Right of use assets – leased	875	1,065
Net book value	$ 62,882	$ 57,372

Property, plant and equipment -

Property, plant and equipment - Summary of property, plant and equipment (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	$ 56,307	$ 56,361
Adjustment for transition to new accounting standard			$ (31)
Restated opening balance			56,330
Adjustment on currency translation	2,888	426
Adjustments to capitalised closure costs	946	840
Amounts capitalised	340	321	296
Additions	6,311	5,530
Depreciation for the year	(3,796)	(3,979)
Impairment charges	(863)	(3,476)
Disposals	(95)	(72)
Transfers and other movements	(31)	387
Property, plant and equipment at end of period	62,007	56,307	56,361
Non-current assets pledged as security	14,245	12,758
Cost
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	112,285
Property, plant and equipment at end of period	121,739	112,285
Accumulated amortisation and impairment
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	(55,978)
Property, plant and equipment at end of period	(59,732)	(55,978)
Mining properties and leases
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	10,402	11,063
Adjustment for transition to new accounting standard			0
Restated opening balance			11,063
Adjustment on currency translation	457	27
Adjustments to capitalised closure costs	946	840
Amounts capitalised	0	0
Additions	329	433
Depreciation for the year	(666)	(729)
Impairment charges	(327)	(1,339)
Disposals	(2)	0
Transfers and other movements	34	107
Property, plant and equipment at end of period	11,173	10,402	11,063
Non-current assets pledged as security	1,712	1,805
Mining properties and leases | Cost
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	24,875
Property, plant and equipment at end of period	25,052	24,875
Mining properties and leases | Accumulated amortisation and impairment
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	(14,473)
Property, plant and equipment at end of period	(13,879)	(14,473)
Land and buildings
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	6,403	6,263
Adjustment for transition to new accounting standard			0
Restated opening balance			6,263
Adjustment on currency translation	307	72
Adjustments to capitalised closure costs	0	0
Amounts capitalised	0	0
Additions	45	46
Depreciation for the year	(354)	(381)
Impairment charges	(85)	(96)
Disposals	(13)	(9)
Transfers and other movements	66	508
Property, plant and equipment at end of period	6,369	6,403	6,263
Non-current assets pledged as security	494	571
Land and buildings | Cost
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	11,517
Property, plant and equipment at end of period	12,178	11,517
Land and buildings | Accumulated amortisation and impairment
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	(5,114)
Property, plant and equipment at end of period	(5,809)	(5,114)
Plant and equipment
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	31,491	32,019
Adjustment for transition to new accounting standard			(31)
Restated opening balance			31,988
Adjustment on currency translation	1,758	286
Adjustments to capitalised closure costs	0	0
Amounts capitalised	0	0
Additions	726	616
Depreciation for the year	(2,776)	(2,869)
Impairment charges	(369)	(1,115)
Disposals	(64)	(44)
Transfers and other movements	1,988	2,629
Property, plant and equipment at end of period	32,754	31,491	32,019
Non-current assets pledged as security	5,065	5,111
Plant and equipment | Cost
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	66,705
Property, plant and equipment at end of period	71,603	66,705
Plant and equipment | Accumulated amortisation and impairment
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	(35,214)
Property, plant and equipment at end of period	(38,849)	(35,214)
Capital works in progress
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	8,011	7,016
Adjustment for transition to new accounting standard			0
Restated opening balance			7,016
Adjustment on currency translation	366	41
Adjustments to capitalised closure costs	0	0
Amounts capitalised	340	321
Additions	5,211	4,435
Depreciation for the year	0	0
Impairment charges	(82)	(926)
Disposals	(16)	(19)
Transfers and other movements	(2,119)	(2,857)
Property, plant and equipment at end of period	11,711	8,011	$ 7,016
Non-current assets pledged as security	6,974	5,271
Capital works in progress | Cost
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	9,188
Property, plant and equipment at end of period	12,906	9,188
Capital works in progress | Accumulated amortisation and impairment
Disclosure of detailed information about property, plant and equipment [Line Items]
Property, plant and equipment at beginning of period	(1,177)
Property, plant and equipment at end of period	$ (1,195)	$ (1,177)

Property, plant and equipment_2

Property, plant and equipment - Summary of property, plant and equipment (Footnotes) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about property, plant and equipment [Line Items]
Depreciation of property, plant and equipment	$ (3,796)	$ (3,979)
Average borrowing rate used for capitalisation of interest	4.20%	5.30%
Loans secured by non-current assets collateral	$ 4,518	$ 4,540
Capitalised production phase stripping costs
Disclosure of detailed information about property, plant and equipment [Line Items]
Capitalised production phase stripping costs, carrying amount	2,398	2,276
Capitalisation of property, plant and equipment	380
Capitalisation offset by depreciation	(267)
Capitalised production phase stripping costs | Property, plant and equipment
Disclosure of detailed information about property, plant and equipment [Line Items]
Capitalised production phase stripping costs, carrying amount	2,019	1,833
Capitalised production phase stripping costs | Investment in equity accounted units
Disclosure of detailed information about property, plant and equipment [Line Items]
Capitalised production phase stripping costs, carrying amount	379	443
Capitalised production phase stripping costs | Subsidiaries
Disclosure of detailed information about property, plant and equipment [Line Items]
Depreciation of property, plant and equipment	$ (145)	(139)	$ (134)
Buildings | Bottom of range
Disclosure of detailed information about property, plant and equipment [Line Items]
Useful lives of property, plant and equipment	5 years
Buildings | Top of range
Disclosure of detailed information about property, plant and equipment [Line Items]
Useful lives of property, plant and equipment	50 years
Plant and equipment
Disclosure of detailed information about property, plant and equipment [Line Items]
Depreciation of property, plant and equipment	$ (2,776)	$ (2,869)
Plant and equipment | Bottom of range
Disclosure of detailed information about property, plant and equipment [Line Items]
Useful lives of property, plant and equipment	3 years
Plant and equipment | Top of range
Disclosure of detailed information about property, plant and equipment [Line Items]
Useful lives of property, plant and equipment	50 years
Power generating assets | Bottom of range
Disclosure of detailed information about property, plant and equipment [Line Items]
Useful lives of property, plant and equipment	25 years
Power generating assets | Top of range
Disclosure of detailed information about property, plant and equipment [Line Items]
Useful lives of property, plant and equipment	50 years

Property, plant and equipment_3

Property, plant and equipment Property, plant, and equipment - Summary of Right-of-Use Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about property, plant and equipment [Line Items]
Net book value	$ 875	$ 1,065
Additions for the year	105	301
Depreciation for the year (included within operating costs)	(322)	(272)
Impairment charges	(904)	(3,487)	$ (132)
Land and buildings
Disclosure of detailed information about property, plant and equipment [Line Items]
Net book value	475	507
Additions for the year	30	89
Depreciation for the year (included within operating costs)	(93)	(69)
Plant and equipment
Disclosure of detailed information about property, plant and equipment [Line Items]
Net book value	400	558
Additions for the year	75	212
Depreciation for the year (included within operating costs)	(229)	(203)
Right-of-use assets
Disclosure of detailed information about property, plant and equipment [Line Items]
Impairment charges	(37)	(10)
Right-of-use assets | Land and buildings
Disclosure of detailed information about property, plant and equipment [Line Items]
Impairment charges	(6)	(6)
Right-of-use assets | Plant and equipment
Disclosure of detailed information about property, plant and equipment [Line Items]
Impairment charges	$ (31)	$ (4)

Investments in equity account_3

Investments in equity accounted units - Summary of Investments in equity accounted units (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Investments in equity accounted units [Line Items]
Non-current assets	$ 76,535	$ 70,499
Current assets	20,855	17,303
Total assets	97,390	87,802
Non-current liabilities	(33,880)	(31,435)
Total liabilities	(45,487)	(42,560)
Rio Tinto's share of net assets	3,764	3,971
Investment in equity accounted units
Disclosure of Investments in equity accounted units [Line Items]
Non-current assets	5,307	5,820
Current assets	1,077	831
Total assets	6,384	6,651
Current liabilities	(785)	(675)
Non-current liabilities	(1,835)	(2,005)
Total liabilities	(2,620)	(2,680)
Rio Tinto's share of net assets	$ 3,764	$ 3,971	$ 4,299

Investments in equity account_4

Investments in equity accounted units - Additional information (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Investments in equity accounted units [Line Items]
Investments in equity accounted units with shares listed on recognised stock exchanges	$ 0	$ 0
Net debt of the group	(664,000,000)	(3,651,000,000)	$ 255,000,000
Investment in equity accounted units
Disclosure of Investments in equity accounted units [Line Items]
Investments in equity accounted units with shares listed on recognised stock exchanges	0	0
Net debt of the group	$ (931,000,000)	$ (1,248,000,000)

Inventories - Summary of invent

Inventories - Summary of inventories (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Classes of current inventories [abstract]
Raw materials and purchased components	$ 640	$ 675
Consumable stores	1,050	925
Work in progress	1,288	1,066
Finished goods and goods for resale	1,113	936
Total inventories	4,091	3,602
Expected to be used within one year	3,917	3,463
Expected to be used after more than one year	$ 174	$ 139

Inventories - Additional inform

Inventories - Additional information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Classes Of Inventories [Line Items]
Inventory write-downs, net of reversals	$ (15)	$ 42
Decrease through write-off, financial assets	35	134
Inventories pledged as security for liabilities	621	611
Previously stated
Classes Of Inventories [Line Items]
Net inventory write- back	$ 50	$ 92

Deferred Taxation - Reconciliat

Deferred Taxation - Reconciliation of changes in deferred tax liability asset (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of changes in deferred tax liability (asset) [abstract]
Deferred tax liability/(asset)	$ (118)	$ (532)
Adjustment on currency translation	(43)	(77)
Credited to the income statement	178	289
Charged/(credited) to statement of comprehensive income	115	77	$ (325)
Other movements	14	125
Deferred tax liability/(asset)	146	(118)	$ (532)
– deferred tax liabilities	(3,239)	(3,220)
Deferred tax assets	$ 3,385	$ 3,102

Deferred Taxation - Deferred ta

Deferred Taxation - Deferred tax liabilities and assets, prior to offsetting of balances (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	$ 6,465	$ 5,967
Deferred tax liabilities	(6,319)	(6,085)
Credited /(charged) to the income statement	178	289
Tax losses
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	1,867	1,847
Credited /(charged) to the income statement	12	(164)
Provisions
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	2,121	1,810
Credited /(charged) to the income statement	188	175
Capital allowances
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	529	604
Deferred tax liabilities	(4,966)	(4,742)
Credited /(charged) to the income statement	(82)	181
Unremitted earnings
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax liabilities	(402)	(411)
Capitalised interest
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax liabilities	(351)	(387)
Post-retirement benefits
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	698	599
Deferred tax liabilities	(224)	(253)
Credited /(charged) to the income statement	9	(18)
Unrealised exchange gains (losses)
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	204	176
Deferred tax liabilities	(7)	(3)
Credited /(charged) to the income statement	25	(21)
Other temporary differences
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	1,046	931
Deferred tax liabilities	(369)	(289)
Credited /(charged) to the income statement	25	141
Tax on unremitted earnings
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Credited /(charged) to the income statement	$ 1	$ (5)

Deferred Taxation - Deferred _2

Deferred Taxation - Deferred tax liabilities and assets, prior to offsetting of balances (Footnotes) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	$ 3,385	$ 3,102
Deferred tax is not recognised on the unremitted earnings of subsidiaries and joint ventures	2,895	3,861
Tax payable on unremitted earnings	112	164
Recognised and unrecognised deferred tax assets	7,226	6,264
Unrecognised deferred tax assets	$ 3,841	$ 3,162
Unused tax losses
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax loss recovery period	1 year	6 years
Deferred tax assets	$ 1,617	$ 1,186

Deferred Taxation - Recognised

Deferred Taxation - Recognised and unrecognised amounts in deferred tax assets (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	$ 3,385	$ 3,102
Unrecognised	3,841	3,162
France
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	0	0
Unrecognised	1,284	1,111
Canada
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	617	492
Unrecognised	574	566
United States of America
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	938	920
Unrecognised	84	51
Australia
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	649	698
Unrecognised	528	316
Mongolia
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	974	704
Unrecognised	540	721
Other countries
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	207	288
Unrecognised	$ 831	$ 397

Deferred Taxation - Recognise_2

Deferred Taxation - Recognised and unrecognised amounts in deferred tax assets (Footnotes) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	$ 3,385	$ 3,102
Unrecognised deferred tax assets	3,841	3,162
Realised or unrealised capital losses
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	$ 551	491
Deferred tax loss recovery period	1 year
Unrecognised deferred tax assets	$ 720	695
Mongolia
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	974	704
Unrecognised deferred tax assets	540	721
Mongolia | Tax losses
Disclosure of temporary difference, unused tax losses and unused tax credits [Line Items]
Deferred tax assets	$ 292	$ 130
Deferred tax loss recovery period	8 years

Receivables and other assets -

Receivables and other assets - Summary of trade and other receivables (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Trade and other receivables [abstract]
Non-current trade receivables	$ 1	$ 1
Non-current other financial receivables	339	286
Non-current receivables relating to net investment in finance leases	29	52
Non-current amounts due from equity accounted units	0	0
Non-current other receivables	369	123
Non-current prepayment of tolling charges to jointly controlled entities	218	221
Non-Current pension supluses	782	984
Non-current other prepayments	58	49
Total	1,796	1,716
Current trade receivables	2,543	2,097
Current other financial receivables	332	453
Current receivables relating to net investment in finance leases	9	11
Current amounts due from equity accounted units	33	38
Current other receivables	422	209
Current prepayment of tolling charges to jointly controlled entities	0	0
Current pension surpluses	0	0
Current other prepayments	305	219
Total	3,644	3,027
Trade receivables	2,544	2,098
Other financial receivables	671	739
Receivables relating to net investment in finance leases	38	63
Amounts due from equity accounted units	33	38
Other receivables	791	332
Prepayment of tolling charges to jointly controlled entities	218	221
Pension surpluses	782	984
Other prepayments	363	268
Total	$ 5,440	$ 4,743

Receivables and other assets _2

Receivables and other assets - Summary of trade and other receivables (Parenthetical) (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Trade and other receivables [abstract]
Net of provisions for doubtful debts	$ (59,000,000)	$ (54,000,000)
Amount held in trust fund, noncurrent	315,000,000	53,000,000
Amount held in trust fund, current	95,000,000	$ 0
Deposits into trust fund	$ (299,000,000)

Other financial assets - Summar

Other financial assets - Summary of other financial assets including non-quasi equity loans to equity accounted units (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Other Assets [Abstract]
Non-current derivative financial instruments	$ 531	$ 308
Non-current equity shares and quoted funds	66	52
Other non-current investments, including loans	231	236
Non-current loans to equity accounted units	1	39
Current derivative financial instruments	134	58
Current equity shares and quoted funds	9	9
Other current investments, including loans	2,668	2,603
Current loans to equity accounted units	40	0
Derivative financial assets	665	366
Equity shares and quoted funds	75	61
Other investments, including loans	2,899	2,839
Loans to equity accounted units	41	39
Other financial assets, non-current	829	635
Other financial assets, current	2,851	2,670
Other financial assets	$ 3,680	$ 3,305

Other financial assets - Summ_2

Other financial assets - Summary of other financial assets including non-quasi equity loans to equity accounted units (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Other Assets [Abstract]
Highly liquid financial assets held in managed investment funds classified as held for trading	$ 2,538	$ 2,584

Cash and cash equivalents - Sum

Cash and cash equivalents - Summary of cash and cash equivalents (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Cash and cash equivalents [abstract]
Cash at bank and in hand	$ 1,150	$ 978
Money market funds, reverse repurchase agreements and other cash equivalents(a)	9,231	7,049
Balance per Group balance sheet and Group cash flow statement	10,381	$ 8,027
Reverse repurchase agreements	1,200
Fair value of collateral	$ 1,260

Cash and cash equivalents - Add

Cash and cash equivalents - Additional information (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of cash and cash equivalents [Line Items]
Restricted cash and cash equivalents	$ 295	$ 315
Repayment of third party borrowings	238	245
Subsidiaries
Disclosure of cash and cash equivalents [Line Items]
Restricted cash and cash equivalents	1,422	1,644
Repayment of third party borrowings	$ 1,215	$ 1,442

Borrowings and other financia_3

Borrowings and other financial liabilities - Summary of detailed information about borrowings (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 13,247	$ 13,093
Current borrowings	584	1,022
Total borrowings	13,831	14,115
Rio Tinto Finance plc Euro Bonds 2.0% due 2020
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	0	0
Current borrowings	0	455
Total borrowings	$ 0	455
Borrowings, interest rate	2.00%
Rio Tinto Finance plc Euro Bonds 2.875% due 2024
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 555	508
Current borrowings	0	0
Total borrowings	$ 555	508
Borrowings, interest rate	2.875%
Rio Tinto Finance (USA) Limited Bonds 3.75% 2025
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 1,299	1,229
Current borrowings	0	0
Total borrowings	$ 1,299	1,229
Borrowings, interest rate	3.75%
Rio Tinto Finance (USA) Limited Bonds 7.125% 2028
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 1,005	958
Current borrowings	0	0
Total borrowings	$ 1,005	958
Borrowings, interest rate	7.125%
Alcan Inc. Debentures 7.25% due 2028
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 109	104
Current borrowings	0	0
Total borrowings	$ 109	104
Borrowings, interest rate	7.25%
Rio Tinto Finance plc Sterling Bonds 4.0% due 2029
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 717	647
Current borrowings	0	0
Total borrowings	$ 717	647
Borrowings, interest rate	4.00%
Alcan Inc. Debentures 7.25% due 2031
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 438	419
Current borrowings	0	0
Total borrowings	$ 438	419
Borrowings, interest rate	7.25%
Alcan Inc. Global Notes 6.125% due 2033
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 744	742
Current borrowings	0	0
Total borrowings	$ 744	742
Borrowings, interest rate	6.125%
Alcan Inc. Global Notes 5.75% due 2035
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 292	289
Current borrowings	0	0
Total borrowings	$ 292	289
Borrowings, interest rate	5.75%
Rio Tinto Finance (USA) Limited Bonds 5.2% 2040
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 1,173	1,137
Current borrowings	0	0
Total borrowings	$ 1,173	1,137
Borrowings, interest rate	5.20%
Rio Tinto Finance (USA) plc Bonds 4.75% 2042
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 501	483
Current borrowings	0	0
Total borrowings	$ 501	483
Borrowings, interest rate	4.75%
Rio Tinto Finance (USA) plc Bonds 4.125% 2042
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 743	716
Current borrowings	0	0
Total borrowings	$ 743	716
Borrowings, interest rate	4.125%
Oyu Tolgoi LLC MIGA Insured Loan LIBOR plus 2.65% due 2027
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 674	676
Current borrowings	4	3
Total borrowings	$ 678	679
Borrowings, interest rate	2.65%
Oyu Tolgoi LLC Commercial Banks, B Loan LIBOR plus 3.4% due 2027
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 1,571	1,581
Current borrowings	10	8
Total borrowings	$ 1,581	1,589
Borrowings, interest rate	3.40%
Oyu Tolgoi LLC Export Credit Agencies Loan 2.3% due 2028
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 275	273
Current borrowings	2	3
Total borrowings	$ 277	276
Borrowings, interest rate	2.30%
Oyu Tolgoi LLC Export Credit Agencies Loan LIBOR plus 3.65% due 2029
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 867	869
Current borrowings	5	5
Total borrowings	$ 872	874
Borrowings, interest rate	3.65%
Oyu Tolgoi LLC International Financial Instritutions, A Loan, LIBOR plus 3.78% due 2030
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 771	771
Current borrowings	6	4
Total borrowings	$ 777	775
Borrowings, interest rate	3.78%
Other secured loans
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	$ 246	302
Current borrowings	68	45
Total borrowings	314	347
Other unsecured loans
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	322	382
Current borrowings	256	197
Total borrowings	578	579
Lease liabilities
Disclosure of detailed information about borrowings [Line Items]
Non-current borrowing	945	1,007
Current borrowings	233	302
Total borrowings	$ 1,178	$ 1,309

Borrowings and other financia_4

Borrowings and other financial liabilities - Summary of detailed information about borrowings (Parenthetical) (Detail) € in Millions, $ in Millions		May 11, 2020EUR (€)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Disclosure of detailed information about borrowings [Line Items]
Notional amount			$ 1,522	$ 1,656
Cumulative amount utilised from debt issuance			1,200	1,600
Carrying value of bonds			1,300	1,600
Buy-back of bonds					$ 1,900
Repayments of borrowings, classified as financing activities	[1]		$ 721	203	$ 2,300
Increase in stated percentage			1.00%
Borrowings			$ 13,831	14,115
Debt instrument restrictive covenants			4,500	4,500
Rio Tinto Finance plc Euro Bonds 2.0% due 2020
Disclosure of detailed information about borrowings [Line Items]
Buy-back of bonds | €		€ 402
Repayments of borrowings, classified as financing activities			526
Borrowings			0	455
European debt issuance programme
Disclosure of detailed information about borrowings [Line Items]
Notional amount			$ 10,000	$ 10,000
[1]	On 11 May 2020, we repaid our €402 million (nominal value) Rio Tinto Finance plc Euro Bonds on their maturity. The cash outflow relating to the repayment of the bonds and the realised loss on the derivatives have been recognised within "Repayment of borrowings and associated derivatives" in the Group cash flow statement and totalled US$526 million.

Borrowings and other financia_5

Borrowings and other financial liabilities - Summary of borrowings and other financial liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of borrowings and other financial liabilities [Line Items]
Borrowings and other financial liabilities	$ 13,408	$ 13,341
Total other current financial liabilities	607	1,372
Total other financial liabilities	0	247
Non-current portion of non-current borrowings	13,247	13,093
Current borrowings	584	1,022
Total borrowings	13,831	14,115
Current borrowings and current portion of non-current borrowings	607	1,372
Borrowings and other financial liabilities	14,015	14,713
Derivative financial instruments
Disclosure of borrowings and other financial liabilities [Line Items]
Borrowings and other financial liabilities	161	248
Total other current financial liabilities	23	103
Total other financial liabilities	184	351
Other financial liabilities
Disclosure of borrowings and other financial liabilities [Line Items]
Borrowings and other financial liabilities	0	0
Total other current financial liabilities	0	247
Total other financial liabilities	0	247
Total other financial liabilities
Disclosure of borrowings and other financial liabilities [Line Items]
Borrowings and other financial liabilities	161	248
Total other current financial liabilities	23	350
Total other financial liabilities	$ 184	$ 598

Leases Leases - Summary of Leas

Leases Leases - Summary of Lease Payments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of leases [Abstract]
Principal lease payments	$ 324	$ 315
Interest payments on leases	50	53
Payments for short-term leases	314	327
Payments for variable lease components	30	15
Payments for low value leases (>12 months in duration)	1	1
Total lease payments	$ 719	$ 711

Leases - Summary of capitalised

Leases - Summary of capitalised finance leases (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Maturity Analysis Of Finance Lease Payments Payable [Line Items]
Total minimum lease payments	$ 1,566	$ 1,670
Effect of discounting	(388)	(361)
Total	1,178	1,309
Due within 1 year
Disclosure Of Maturity Analysis Of Finance Lease Payments Payable [Line Items]
Total minimum lease payments	271	349
Between 1 and 3 years
Disclosure Of Maturity Analysis Of Finance Lease Payments Payable [Line Items]
Total minimum lease payments	386	424
Between 3 and 5 years
Disclosure Of Maturity Analysis Of Finance Lease Payments Payable [Line Items]
Total minimum lease payments	185	226
More than 5 years
Disclosure Of Maturity Analysis Of Finance Lease Payments Payable [Line Items]
Total minimum lease payments	$ 724	$ 671

Leases - Narrative (Detail)

Leases - Narrative (Detail) - I F R S16 - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of initial application of standards or interpretations [Line Items]
Lease commitments, not commenced	$ 125	$ 119
Leases expiring in 12 months or fewer	$ 155	$ 108

Consolidated net cash_(debt) -

Consolidated net cash/(debt) - Analysis of changes in consolidated net cash/(debt) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Disclosure of financial liabilities [Abstract]
Net debt at beginning balance	$ (3,651)	$ 255
Net debt, Adjustment for transition to new accounting standards			$ (1,248)
Foreign exchange adjustment	74	(65)
Cash movements excluding exchange movements, net debt	3,051	(2,342)
Other non-cash movements	(138)	(251)
Net debt at ending balance	(664)	(3,651)
Borrowings excluding overdrafts
Disclosure of financial liabilities [Abstract]
Financial liabilities, beginning balance	(12,806)	(12,707)
Financial liabilities, adjustment for transition to new accounting standards			0
Foreign exchange adjustment	(83)	(5)
Cash movements excluding exchange movements	505	123
Other non-cash movements	(269)	(217)
Financial liabilities, ending balance	(12,653)	(12,806)
Lease liabilities
Disclosure of financial liabilities [Abstract]
Financial liabilities, beginning balance	(1,309)	(44)
Lease liabilities			(1,248)
Foreign exchange adjustment	(47)	(9)
Cash movements excluding exchange movements	324	315
Other non-cash movements	(146)	(323)
Financial liabilities, ending balance	(1,178)	(1,309)
Debt-related derivatives (included in other financial assets/liabilities
Disclosure of financial liabilities [Abstract]
Financial liabilities, beginning balance	(147)	(288)
Financial liabilities, adjustment for transition to new accounting standards			0
Foreign exchange adjustment	39	3
Cash movements excluding exchange movements	91	0
Other non-cash movements	265	138
Financial liabilities, ending balance	248	(147)
Cash and cash equivalents
Disclosure of financial liabilities [Abstract]
Cash and cash equivalents and other investments, beginning balance	8,027	10,772
Cash and cash equivalents and other investments, adjustment for transition to new accounting standards			0
Foreign exchange adjustment	165	(54)
Cash movements excluding exchange movements	2,189	(2,808)
Other non-cash movements	0	117
Cash and cash equivalents and other investments, ending balance	10,381	8,027
Other Investments
Disclosure of financial liabilities [Abstract]
Cash and cash equivalents and other investments, beginning balance	2,584	2,522
Cash and cash equivalents and other investments, adjustment for transition to new accounting standards			$ 0
Foreign exchange adjustment	0	0
Cash movements excluding exchange movements	(58)	28
Other non-cash movements	12	34
Cash and cash equivalents and other investments, ending balance	$ 2,538	$ 2,584

Consolidated net cash_(debt) _2

Consolidated net cash/(debt) - Analysis of changes in consolidated net cash/(debt) (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of financial liabilities [Abstract]
Borrowings	$ 13,831	$ 14,115
Borrowings and other financial liabilities	14,015	14,713
Total other current financial liabilities	607	1,372
Other non-current financial liabilities	13,408	13,341
Other differences to cash and cash equivalents in statement of cash flows		117
Highly liquid financial assets held in managed investment funds classified as held for trading	2,538	2,584
Borrowings Excluding Overdrafts, Including Lease Liabilities
Disclosure of financial liabilities [Abstract]
Borrowings	13,831	14,115
Total other financial liabilities
Disclosure of financial liabilities [Abstract]
Total other current financial liabilities	23	350
Other non-current financial liabilities	$ 161	$ 248

Trade and other payables - Summ

Trade and other payables - Summary of Trade and other payables (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Trade and other payables [abstract]
Non-current trade payables	$ 1	$ 0
Non-current other financial payables	298	272
Other non-current payables	97	110
Non-current deferred income	133	143
Non-current accruals	27	27
Non-current employee entitlements	0	0
Noncurrent Royalties And Mining Taxes	3	4
Non-current amounts owed to equity accounted units	190	167
Non-current government grants	71	71
Total	820	794
Current trade payables	3,124	2,855
Other Current Financial Payables	862	668
Other current payables	115	97
Current deferred income	344	200
Current accruals	1,294	1,305
Current employee entitlements	762	650
Current royalties and mining taxes	863	596
Current amounts owed to equity accounted units	51	104
Current government grants	6	5
Total	7,421	6,480
Trade payables	3,125	2,855
Other financial payables	1,160	940
Other payables	212	207
Deferred income	477	343
Accruals	1,321	1,332
Employee entitlements	762	650
Royalties And Mining Taxes	866	600
Amounts Owed To Equity Accounted Units	241	271
Government grants	77	76
Total	$ 8,241	$ 7,274

Trade and other payables - Su_2

Trade and other payables - Summary of Trade and other payables (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Trade and other payables [abstract]
Contract liabilities	$ 338	$ 158

Provisions, including post-reti

Provisions, including post-retirement benefits - Summary of Provisions, including post-retirement benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of other provisions [Line Items]
Provisions (including post-retirement benefits) at beginning balance	$ 15,103	$ 13,608
Adjustment to opening balance on transition to new accounting standard(d)				$ 0	$ (66)
Restated opening balance				15,103	13,542
Adjustment on currency translation	890	65
Adjustments to mining properties/right of use assets:
– increases to existing and new provisions	141	840
– change in discount rate	816	0
Charged/(credited) to profit:
– increases to existing and new provisions	1,074	850
– change in discount rate	140	0
– unused amounts reversed	(299)	(100)
– exchange losses on provisions	(22)	3
– amortisation of discount	377	387
Utilised in year	(774)	(744)
Actuarial losses recognised in equity	250	235
Transfers and other movements	(31)	25
Provisions (including post-retirement benefits) at ending balance	17,665	15,103
Balance sheet analysis:
Current			$ 1,729	1,399
Non-current			15,936	13,704
Total	15,103	15,103	17,665	15,103	$ 13,608
Pensions and post retirement healthcare
Disclosure of other provisions [Line Items]
Provisions (including post-retirement benefits) at beginning balance	2,714
Adjustment to opening balance on transition to new accounting standard(d)				0
Restated opening balance				2,714
Adjustment on currency translation	83
Adjustments to mining properties/right of use assets:
– increases to existing and new provisions	0
– change in discount rate	0
Charged/(credited) to profit:
– increases to existing and new provisions	200
– change in discount rate	0
– unused amounts reversed	0
– exchange losses on provisions	0
– amortisation of discount	0
Utilised in year	(192)
Actuarial losses recognised in equity	250
Transfers and other movements	0
Provisions (including post-retirement benefits) at ending balance	3,055	2,714
Balance sheet analysis:
Current			70
Non-current			2,985
Total	3,055	2,714	3,055	2,714
Other employee entitlements
Disclosure of other provisions [Line Items]
Provisions (including post-retirement benefits) at beginning balance	354
Adjustment to opening balance on transition to new accounting standard(d)				0
Restated opening balance				354
Adjustment on currency translation	34
Adjustments to mining properties/right of use assets:
– increases to existing and new provisions	0
– change in discount rate	0
Charged/(credited) to profit:
– increases to existing and new provisions	127
– change in discount rate	0
– unused amounts reversed	(19)
– exchange losses on provisions	0
– amortisation of discount	0
Utilised in year	(77)
Actuarial losses recognised in equity	0
Transfers and other movements	0
Provisions (including post-retirement benefits) at ending balance	419	354
Balance sheet analysis:
Current			327
Non-current			92
Total	419	354	419	354
Close down and restoration/ environmental
Disclosure of other provisions [Line Items]
Provisions (including post-retirement benefits) at beginning balance	11,090
Adjustment to opening balance on transition to new accounting standard(d)				0
Restated opening balance				11,090
Adjustment on currency translation	736
Adjustments to mining properties/right of use assets:
– increases to existing and new provisions	130
– change in discount rate	816
Charged/(credited) to profit:
– increases to existing and new provisions	562
– change in discount rate	138
– unused amounts reversed	(123)
– exchange losses on provisions	(21)
– amortisation of discount	373
Utilised in year	(366)
Actuarial losses recognised in equity	0
Transfers and other movements	0
Provisions (including post-retirement benefits) at ending balance	13,335	11,090
Balance sheet analysis:
Current			777
Non-current			12,558
Total	11,090	11,090	13,335	11,090
Other
Disclosure of other provisions [Line Items]
Provisions (including post-retirement benefits) at beginning balance	945
Adjustment to opening balance on transition to new accounting standard(d)				0
Restated opening balance				945
Adjustment on currency translation	37
Adjustments to mining properties/right of use assets:
– increases to existing and new provisions	11
– change in discount rate	0
Charged/(credited) to profit:
– increases to existing and new provisions	185
– change in discount rate	2
– unused amounts reversed	(157)
– exchange losses on provisions	(1)
– amortisation of discount	4
Utilised in year	(139)
Actuarial losses recognised in equity	0
Transfers and other movements	(31)
Provisions (including post-retirement benefits) at ending balance	856	945
Balance sheet analysis:
Current			555
Non-current			301
Total	$ 856	$ 945	$ 856	$ 945

Provisions (including post-re_3

Provisions (including post-retirement benefits) - Undiscounted Close-Down and Environmental Restoration Obligation (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of other provisions [Line Items]
Undiscounted close-down and environmental restoration cash flows	$ 17,400	$ 16,066
Impact of discounting	(4,065)	(4,976)
Total closure obligation	13,335	11,090
United States of America
Disclosure of other provisions [Line Items]
Total closure obligation	3,819	3,377
Australia
Disclosure of other provisions [Line Items]
Total closure obligation	7,076	5,610
Canada
Disclosure of other provisions [Line Items]
Total closure obligation	1,482	1,267
Rest of World
Disclosure of other provisions [Line Items]
Total closure obligation	958	836
Decommissioning, decontamination and demolition
Disclosure of other provisions [Line Items]
Total closure obligation	3,131	2,066
Closure and rehabilitation earthworks
Disclosure of other provisions [Line Items]
Total closure obligation	4,223	3,889
Long term water management costs
Disclosure of other provisions [Line Items]
Total closure obligation	966	920
Post closure monitoring and maintenance
Disclosure of other provisions [Line Items]
Total closure obligation	1,318	855
Indirect costs, owners costs and estimating contingency
Disclosure of other provisions [Line Items]
Total closure obligation	3,697	3,360
Operating sites
Disclosure of other provisions [Line Items]
Total closure obligation	10,736	9,255
Non-operating sites
Disclosure of other provisions [Line Items]
Total closure obligation	2,599	1,835
Due within 1 year
Disclosure of other provisions [Line Items]
Undiscounted close-down and environmental restoration cash flows	776	541
Between 1 and 3 years
Disclosure of other provisions [Line Items]
Undiscounted close-down and environmental restoration cash flows	1,203	955
Between 3 and 5 years
Disclosure of other provisions [Line Items]
Undiscounted close-down and environmental restoration cash flows	1,433	1,100
More than 5 years
Disclosure of other provisions [Line Items]
Undiscounted close-down and environmental restoration cash flows	$ 13,988	$ 13,470

Provisions, including post-re_2

Provisions, including post-retirement benefits - Summary of Provisions, including post-retirement benefits (Parenthetical) (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of other provisions [Line Items]
Non-current provisions		$ 15,936	$ 13,704
Remaining lives of operations and infrastructure		one to over 50 years
Remaining lives of operations and infrastructure present closure obligation		17 years	18 years
Provisions		$ 17,665	$ 15,103	$ 13,608
Risk free interest rate on provisions	1.50%	1.50%	2.00%
Bottom of range
Disclosure of other provisions [Line Items]
Provisions		$ 2,600
Risk free interest rate on provisions		1.00%
Top of range
Disclosure of other provisions [Line Items]
Provisions		$ 1,300
Risk free interest rate on provisions		3.00%
Other employee entitlements
Disclosure of other provisions [Line Items]
Provision for long service leave		$ 283	$ 248
Provision for redundancy and severance payments		62	30
Non-current provisions		92
Provisions		419	354
Close down and restoration/ environmental
Disclosure of other provisions [Line Items]
Non-current provisions		12,558
Provisions		13,335	11,090
Close down and restoration/ environmental | Diavik Diamond Mines (2012) Inc.
Disclosure of other provisions [Line Items]
Provisions relating to insurance recoveries and other financial assets held		574	166
Close down and restoration/ environmental | Between 1 and 5 years
Disclosure of other provisions [Line Items]
Non-current provisions		468	382
Close down and restoration/ environmental | More than 5 years
Disclosure of other provisions [Line Items]
Non-current provisions		937	$ 883
Close down and restoration/ environmental | Bottom of range
Disclosure of other provisions [Line Items]
Provision capitalised to property, plant and equipment		2,400
Provision charged to the income statement		200
Close down and restoration/ environmental | Top of range
Disclosure of other provisions [Line Items]
Provision capitalised to property, plant and equipment		1,200
Provision charged to the income statement		$ 100

Share capital - Rio Tinto plc -

Share capital - Rio Tinto plc - Summary of share capital (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of classes of share capital [line items]
Ordinary shares issued	$ 0	$ 0	$ 0
Number of shares held (in shares)	0	0	0
Rio Tinto plc
Disclosure of classes of share capital [line items]
Number of issued and fully paid up share capital at beginning balance (in shares)	1,259,345,000	1,287,660,000	1,351,609,000
Issued and fully paid up share capital at beginning balance	$ 207	$ 211	$ 220
Ordinary shares issued (in shares)	39,000	41,000	35,000
Shares purchased and cancelled (in shares)	(3,627,568)	(28,356,034)	(63,984,287)
Shares purchased and cancelled	$ 0	$ (4)	$ (9)
Issued and fully paid up share capital at ending balance	$ 207	$ 207	$ 211
Number of shares held by public at beginning balance	1,259,345,000	1,287,660,000
Number of issued and fully paid up share capital at ending balance (in shares)	1,255,756,000	1,259,345,000	1,287,660,000
Number of shares held by public at ending balance	1,255,756,000	1,259,345,000	1,287,660,000
Rio Tinto plc | Shares held by public
Disclosure of classes of share capital [line items]
Ordinary shares issued (in shares)	39,000	41,000	35,000
Number of shares held (in shares)	8,852,000	9,421,000	9,445,000
Shares purchased and cancelled (in shares)	3,628,000	28,356,000	63,984,000
Number of shares held by public at beginning balance	1,249,924,000	1,278,215,000	1,342,058,000
Shares reissued from treasury	569,000	24,000	106,000
Number of shares held by public at ending balance	1,246,904,000	1,249,924,000	1,278,215,000
Rio Tinto plc | Special voting share
Disclosure of classes of share capital [line items]
Other share classes	1 only	1 only	1 only
Rio Tinto plc | DLC dividend share
Disclosure of classes of share capital [line items]
Other share classes	1 only	1 only	1 only
Rio Tinto plc | Equalisation share
Disclosure of classes of share capital [line items]
Other share classes	1 only	1 only	1 only

Share capital - Rio Tinto plc_2

Share capital - Rio Tinto plc - Summary of share capital (Parenthetical) (Detail) - Rio Tinto plc $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)shares	Dec. 31, 2020USD ($)£ / sharesshares	Dec. 31, 2019USD ($)shares	Dec. 31, 2019USD ($)£ / sharesshares	Dec. 31, 2018USD ($)shares	Dec. 31, 2018USD ($)£ / sharesshares	Dec. 31, 2017USD ($)
Disclosure of classes of share capital [line items]
Ordinary shares issued (in shares)			40,974	40,974	35,380	35,380
Number of shares bought back	3,627,568		28,356,034		63,984,287
Share capital | $	$ 207	$ 207	$ 207	$ 207	$ 211	$ 211	$ 220
Treasury stock reissued | $	$ 1		$ 1		$ 6
Rio Tinto Plc employee share based payment plans
Disclosure of classes of share capital [line items]
Ordinary shares issued (in shares)	0	0	0	0	0	0
Exercise prices per share | £ / shares		$ 32.74		$ 36.33		$ 16.53
Market value per share | £ / shares		$ 56.32		$ 49.74		$ 43.79
Rio Tinto Plc employee share based payment plans | Treasury shares
Disclosure of classes of share capital [line items]
Shares reissued from treasury	568,863		23,659		106,045
Global employee share plan
Disclosure of classes of share capital [line items]
Ordinary shares issued (in shares)	39,273	39,273
Share capital | $	$ 1.3	$ 1.3	$ 1.1	$ 1.1	$ 1	$ 1

Share capital - Rio Tinto plc_3

Share capital - Rio Tinto plc - Additional information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
American depository receipts
Disclosure of classes of share capital [line items]
Value of shares purchased by employee share ownership trusts	$ 31	$ 43	$ 140
Rio Tinto plc
Disclosure of classes of share capital [line items]
Shares held in the employee share ownership trusts on behalf of Rio Tinto plc	273,902
Rio Tinto plc | American depository receipts
Disclosure of classes of share capital [line items]
American Depository Reciepts In Entity Held In Employee Share Ownership Trust	41,240

Share capital - Rio Tinto Lim_3

Share capital - Rio Tinto Limited - Summary of share capital (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Nov. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of classes of share capital [line items]
Adjustment on currency translation		$ 205	$ 60
Rio Tinto Limited
Disclosure of classes of share capital [line items]
Number of issued and fully paid up share capital at beginning balance (in shares)		371,210,000	371,210,000	412,410,000
Shares purchased and cancelled (in shares)	(41,198,134)	0	0	(41,200,000)
Number of issued and fully paid up share capital at ending balance (in shares)		371,210,000	371,210,000	371,210,000
Issued and fully paid up share capital at beginning balance		$ 3,448	$ 3,477	$ 4,140
Adjustment on currency translation		333	(29)	(382)
Ordinary shares purchased and cancelled		0	0	(281)
Issued and fully paid up share capital at ending balance		$ 3,781	$ 3,448	$ 3,477
Rio Tinto Limited | Special voting share
Disclosure of classes of share capital [line items]
Other share classes		1 only	1 only	1 only
Rio Tinto Limited | DLC dividend share
Disclosure of classes of share capital [line items]
Other share classes		1 only	1 only	1 only

Share capital - Rio Tinto Lim_4

Share capital - Rio Tinto Limited - Summary of share capital (Parenthetical) (Detail) - Rio Tinto Limited - $ / shares	1 Months Ended	12 Months Ended
	Nov. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of classes of share capital [line items]
Ordinary shares purchased and cancelled	41,198,134	0	0	41,200,000
Price per purchased share	$ 69.69
Top of range
Disclosure of classes of share capital [line items]
Number of shares bought back	41,200,000

Share capital - Rio Tinto Lim_5

Share capital - Rio Tinto Limited - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of classes of share capital [line items]
Number of shares held (in shares)	0	0	0
Rio Tinto Limited
Disclosure of classes of share capital [line items]
Value of shares purchased by employee share ownership trusts	$ 76	$ 63	$ 114
Number of shares held (in shares)	828,338

Other reserves and retained e_3

Other reserves and retained earnings - Summary of other reserves and retained earnings (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Other Reserves And Retained Earnings [Line Items]
Beginning balance		$ 9,177
Own shares purchased from Rio Tinto Limited shareholders to satisfy share options				$ 0
Employee share options: value of services	[1]	(107)	$ (106)	(254)
Ending balance		11,960	9,177
Parent and subsidiaries' currency translation and exchange adjustments		(74)	65
Beginning balance		23,387
Equity accounted units' profit after tax for the year		652	301	513
Tax relating to components of other comprehensive income		115	77	(325)
Dividends paid		(6,821)	(10,710)	(5,771)
Employee share options and other IFRS 2 charges to the income statement		143	126	111
Ending balance		26,792	23,387
Capital redemption reserve
Disclosure Of Other Reserves And Retained Earnings [Line Items]
Beginning balance		51	47	38
Own shares purchased and cancelled		0	4	9
Ending balance		51	51	47
Cash flow hedge reserve
Disclosure Of Other Reserves And Retained Earnings [Line Items]
Beginning balance		160	195	32
Adjustment for transition to new accounting pronouncements		0	0	(4)
Cash flow hedge gains		24	12	156
Cash flow hedge (gains)/losses transferred to the income statement		(63)	(41)	40
Tax on the above		3	(6)	(54)
Transfers and other movements		0	0	25
Ending balance		124	160	195
Available for sale revaluation reserves
Disclosure Of Other Reserves And Retained Earnings [Line Items]
Beginning balance		0	0	20
Adjustment for transition to new accounting pronouncements		0	0	(20)
Gains on available for sale securities		0	0	0
Losses on available for sale securities transferred to the income statement		0	0	0
Tax on the above		0	0	0
Transfers and other movements		0	0	0
Ending balance		0	0	0
Fair value through other comprehensive income reserve
Disclosure Of Other Reserves And Retained Earnings [Line Items]
Beginning balance		(11)	(6)	0
Adjustment for transition to new accounting pronouncements		0	0	8
Losses on equity investments		9	(5)	(11)
Transfers to retained earnings		0	0	(3)
Ending balance		(2)	(11)	(6)
Cost of hedging reserve
Disclosure Of Other Reserves And Retained Earnings [Line Items]
Beginning balance		(10)	(13)	0
Adjustment for transition to new accounting pronouncements		0	0	26
Cost of hedging deferred to reserves during the year		7	3	(36)
Transfer of cost of hedging to the income statement		0	0	(3)
Ending balance		(3)	(10)	(13)
Other reserves
Disclosure Of Other Reserves And Retained Earnings [Line Items]
Beginning balance		11,643	11,650	11,714
Own shares purchased from Rio Tinto Limited shareholders to satisfy share options		(76)	(63)	(114)
Employee share options: value of services		60	52	52
Deferred tax on share options		1	4	(2)
Ending balance		11,628	11,643	11,650
Foreign currency translation reserve
Disclosure Of Other Reserves And Retained Earnings [Line Items]
Beginning balance		9,177	8,661
Ending balance		11,960	9,177	8,661
Beginning balance		(2,656)	(3,212)	480
Parent and subsidiaries' currency translation and exchange adjustments		2,814	331	(3,658)
Equity accounted units currency translation adjustments		4	10	(48)
Currency translation reclassified on disposal		0	215	14
Ending balance		162	(2,656)	(3,212)
Retained earnings
Disclosure Of Other Reserves And Retained Earnings [Line Items]
Own shares purchased from Rio Tinto Limited shareholders to satisfy share options				(22)
Employee share options: value of services	[1]	(31)	(43)	(140)
Beginning balance		23,387	27,025	23,761
Adjustment for transition to new accounting pronouncements		0	(113)	(179)
Parent and subsidiaries' profit for the year		9,456	7,709	13,125
Equity accounted units' profit after tax for the year		313	301	513
Actuarial (losses)/gains		(482)	(259)	894
Tax relating to components of other comprehensive income		116	81	(269)
Total comprehensive income for the year		9,403	7,832	14,263
Share buy-back programme		(1)	(1,135)	(5,423)
Dividends paid		(6,132)	(10,334)	(5,356)
Own shares purchased/treasury shares reissued for share options and other movements		(31)	(43)	(140)
Employee share options and other IFRS 2 charges to the income statement		82	70	61
Transfer from FVOCI reserve		0	0	3
Transfers and other movements		0	0	(25)
Ending balance		$ 26,792	$ 23,387	$ 27,025
[1]	Net of contributions received from employees for share awards and share options.

Other reserves and retained e_4

Other reserves and retained earnings - Summary of other reserves and retained earnings (Parenthetical) (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Other Reserves And Retained Earnings [Line Items]
Other reserve, share premium	$ 11,960,000,000	$ 9,177,000,000
Changes in financial assumptions (loss)	1,242,000,000	1,295,000,000	$ (1,382,000,000)
Investment in equity accounted units
Disclosure Of Other Reserves And Retained Earnings [Line Items]
Changes in financial assumptions (loss)	11,000,000	$ 7,000,000	$ 0
Merger reserve
Disclosure Of Other Reserves And Retained Earnings [Line Items]
Other reserve, share premium	$ 11,936,000,000

Financial instruments and ris_3

Financial instruments and risk management - Summary of financial assets and liabilities by categories (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of financial assets [Line Items]
Cash and cash equivalents	$ 10,381	$ 8,027
Trade and other financial receivables	3,286	2,938
Equity shares and quoted funds	75	61
Other investments, including loans	2,899	2,839
Loans to equity accounted units including quasi equity loans	153	152
Total	17,459	14,383
Trade And Other Financial Payables	(5,847)	(5,398)
Short-term borrowings and bank overdrafts	(584)	(1,022)
Medium-term and long-term borrowings	(13,247)	(13,093)
Derivatives and embedded derivatives not related to net debt: not designated as hedges	(24)
Embedded derivatives not related to net debt: designated as hedges	(20)	(24)
Other financial liabilities	0	(247)
Total financial liabilities	(19,862)	(20,111)
Highly liquid financial assets held in managed investment funds classified as held for trading	2,538	2,584
Amortised Cost
Disclosure of financial assets [Line Items]
Cash and cash equivalents	3,970	2,707
Trade and other financial receivables	1,479	1,801
Equity shares and quoted funds	0	0
Other investments, including loans	138	21
Loans to equity accounted units including quasi equity loans	153	152
Total	5,740	4,681
Fair value through other comprehensive income
Disclosure of financial assets [Line Items]
Cash and cash equivalents	0	0
Trade and other financial receivables	0	0
Equity shares and quoted funds	64	50
Other investments, including loans	0	0
Loans to equity accounted units including quasi equity loans	0	0
Total	64	50
Fair value through profit and loss
Disclosure of financial assets [Line Items]
Cash and cash equivalents	6,411	5,320
Trade and other financial receivables	1,807	1,137
Equity shares and quoted funds	11	11
Other investments, including loans	2,761	2,818
Loans to equity accounted units including quasi equity loans	0	0
Total	11,655	9,652
Fair value through profit loss
Disclosure of financial assets [Line Items]
Trade And Other Financial Payables	(30)	(57)
Short-term borrowings and bank overdrafts	0	0
Medium-term and long-term borrowings	0	0
Derivatives and embedded derivatives not related to net debt: not designated as hedges	(24)
Embedded derivatives not related to net debt: designated as hedges	(20)	(24)
Other financial liabilities	0	0
Total financial liabilities	(214)	(408)
Financial liabilities at amortised cost, category
Disclosure of financial assets [Line Items]
Trade And Other Financial Payables	(5,817)	(5,341)
Short-term borrowings and bank overdrafts	(584)	(1,022)
Medium-term and long-term borrowings	(13,247)	(13,093)
Derivatives and embedded derivatives not related to net debt: not designated as hedges	0
Embedded derivatives not related to net debt: designated as hedges	0	0
Other financial liabilities	0	(247)
Total financial liabilities	(19,648)	(19,703)
Fair Value Hedges Related to Debt
Disclosure of financial assets [Line Items]
Derivatives related to net debt: designated as hedges	388	151
Embedded derivatives not related to net debt: designated as hedges	73	66
Derivatives related to net debt: designated as hedges	(140)	(298)
Fair Value Hedges Related to Debt | Amortised Cost
Disclosure of financial assets [Line Items]
Derivatives related to net debt: designated as hedges	0	0
Embedded derivatives not related to net debt: designated as hedges	0	0
Fair Value Hedges Related to Debt | Fair value through other comprehensive income
Disclosure of financial assets [Line Items]
Derivatives related to net debt: designated as hedges	0	0
Embedded derivatives not related to net debt: designated as hedges	0	0
Fair Value Hedges Related to Debt | Fair value through profit and loss
Disclosure of financial assets [Line Items]
Derivatives related to net debt: designated as hedges	388	151
Embedded derivatives not related to net debt: designated as hedges	73	66
Fair Value Hedges Related to Debt | Fair value through profit loss
Disclosure of financial assets [Line Items]
Derivatives related to net debt: designated as hedges	(140)	(298)
Fair Value Hedges Related to Debt | Financial liabilities at amortised cost, category
Disclosure of financial assets [Line Items]
Derivatives related to net debt: designated as hedges	0	0
Fair Value Hedges Excluding Net Debt
Disclosure of financial assets [Line Items]
Derivatives and embedded derivatives not related to net debt: not designated as hedges	204	149
Derivatives and embedded derivatives not related to net debt: not designated as hedges		(29)
Fair Value Hedges Excluding Net Debt | Amortised Cost
Disclosure of financial assets [Line Items]
Derivatives and embedded derivatives not related to net debt: not designated as hedges	0	0
Fair Value Hedges Excluding Net Debt | Fair value through other comprehensive income
Disclosure of financial assets [Line Items]
Derivatives and embedded derivatives not related to net debt: not designated as hedges	0	0
Fair Value Hedges Excluding Net Debt | Fair value through profit and loss
Disclosure of financial assets [Line Items]
Derivatives and embedded derivatives not related to net debt: not designated as hedges	$ 204	149
Fair Value Hedges Excluding Net Debt | Fair value through profit loss
Disclosure of financial assets [Line Items]
Derivatives and embedded derivatives not related to net debt: not designated as hedges		(29)
Fair Value Hedges Excluding Net Debt | Financial liabilities at amortised cost, category
Disclosure of financial assets [Line Items]
Derivatives and embedded derivatives not related to net debt: not designated as hedges		$ 0

Financial instruments and ris_4

Financial instruments and risk management - Capital and liquidity risk - Additional information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about financial instruments [line items]
Net debt of the group	$ (664)	$ (3,651)	$ 255
Borrowings	$ 13,831	14,115
Liquidity risk
Disclosure of detailed information about financial instruments [line items]
Net debt of the group		$ (3,700)
Net debt to total capital percentage	1.00%	7.00%
Description of interest coverage on debt	39	28
Capital And Liquidity Risk Management
Disclosure of detailed information about financial instruments [line items]
Net debt of the group	$ (664)	$ (3,651)
Bottom of range | Liquidity risk
Disclosure of detailed information about financial instruments [line items]
Percentage of underlying earnings	40.00%
Top of range | Liquidity risk
Disclosure of detailed information about financial instruments [line items]
Percentage of underlying earnings	60.00%
Credit Facility Due November 2022 | Liquidity risk
Disclosure of detailed information about financial instruments [line items]
Borrowings	$ 7,500

Financial instruments and ris_5

Financial instruments and risk management - Summary of capital and liquidity risk management (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about hedging instruments [Line Items]
Equity attributable to owners of Rio Tinto	$ 47,054	$ 40,532	$ 43,686
Equity attributable to non-controlling interests	4,849	4,710
Net debt	664	3,651	$ (255)
Capital And Liquidity Risk Management
Disclosure of detailed information about hedging instruments [Line Items]
Equity attributable to owners of Rio Tinto	47,054	40,532
Equity attributable to non-controlling interests	4,849	4,710
Net debt	664	3,651
Total capital	$ 52,567	$ 48,893

Financial instruments and ris_6

Financial instruments and risk management - Maturity analysis for non-derivative financial liabilities and derivative financial liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of maturity analysis for derivative financial liabilities [line items]
Trade and other financial payables	$ (5,766)	$ (5,307)
Expected lease liability payments	(1,566)	(1,670)
Borrowings before swaps	(12,386)	(12,829)
Expected future interest payments	(5,437)	(6,374)
Other financial liabilities	0	(247)
Derivatives related to net debt – net settled	0	(39)
– gross inflows	925	1,910
– gross outflows	(1,113)	(2,323)
Derivatives not related to net debt – net settled	(42)	(60)
– gross inflows	290	699
– gross outflows	(291)	(703)
Total	(25,386)	(26,943)
Due within 1 year
Disclosure of maturity analysis for derivative financial liabilities [line items]
Trade and other financial payables	(5,251)	(4,841)
Expected lease liability payments	(271)	(349)
Borrowings before swaps	(351)	(723)
Expected future interest payments	(525)	(607)
Other financial liabilities		(247)
Derivatives related to net debt – net settled	0	(16)
– gross inflows	27	495
– gross outflows	(34)	(588)
Derivatives not related to net debt – net settled	(20)	(31)
– gross inflows	290	699
– gross outflows	(291)	(703)
Total	(6,426)	(6,911)
Between 1 and 2 years
Disclosure of maturity analysis for derivative financial liabilities [line items]
Trade and other financial payables	(53)	(45)
Expected lease liability payments	(231)	(267)
Borrowings before swaps	(667)	(171)
Expected future interest payments	(522)	(594)
Other financial liabilities		0
Derivatives related to net debt – net settled	0	(16)
– gross inflows	27	40
– gross outflows	(34)	(53)
Derivatives not related to net debt – net settled	(7)	0
– gross inflows	0	0
– gross outflows	0	0
Total	(1,487)	(1,106)
Between 2 and 3 years
Disclosure of maturity analysis for derivative financial liabilities [line items]
Trade and other financial payables	(15)	(12)
Expected lease liability payments	(155)	(157)
Borrowings before swaps	(743)	(665)
Expected future interest payments	(495)	(590)
Other financial liabilities		0
Derivatives related to net debt – net settled	0	(16)
– gross inflows	27	40
– gross outflows	(34)	(53)
Derivatives not related to net debt – net settled	(2)	0
– gross inflows	0	0
– gross outflows	0	0
Total	(1,417)	(1,453)
Between 3 and 4 years
Disclosure of maturity analysis for derivative financial liabilities [line items]
Trade and other financial payables	(34)	(14)
Expected lease liability payments	(101)	(133)
Borrowings before swaps	(1,256)	(741)
Expected future interest payments	(469)	(551)
Other financial liabilities		0
Derivatives related to net debt – net settled	0	9
– gross inflows	27	40
– gross outflows	(34)	(53)
Derivatives not related to net debt – net settled	(2)	(2)
– gross inflows	0	0
– gross outflows	0	0
Total	(1,869)	(1,445)
Between 4 and 5 years
Disclosure of maturity analysis for derivative financial liabilities [line items]
Trade and other financial payables	(19)	(15)
Expected lease liability payments	(84)	(93)
Borrowings before swaps	(1,892)	(1,209)
Expected future interest payments	(427)	(514)
Other financial liabilities		0
Derivatives related to net debt – net settled	0	(3)
– gross inflows	27	507
– gross outflows	(34)	(599)
Derivatives not related to net debt – net settled	(2)	(4)
– gross inflows	0	0
– gross outflows	0	0
Total	(2,431)	(1,930)
More than 5 years
Disclosure of maturity analysis for derivative financial liabilities [line items]
Trade and other financial payables	(394)	(380)
Expected lease liability payments	(724)	(671)
Borrowings before swaps	(7,477)	(9,320)
Expected future interest payments	(2,999)	(3,518)
Other financial liabilities		0
Derivatives related to net debt – net settled	0	3
– gross inflows	790	788
– gross outflows	(943)	(977)
Derivatives not related to net debt – net settled	(9)	(23)
– gross inflows	0	0
– gross outflows	0	0
Total	$ (11,756)	$ (14,098)

Financial instruments and ris_7

Financial instruments and risk management - Commodity price risk - Additional information (Detail) - Commodity price risk - Copper lb in Millions	12 Months Ended
	Dec. 31, 2020USD ($)lb	Dec. 31, 2019USD ($)lb
Disclosure of detailed information about financial instruments [line items]
Quantity of unsettled copper sales | lb	261	220
Provisionally priced unsettled copper sales per pound	$ 336	$ 271
Increase (decrease) in net earnings due to price change	$ 58,000,000	$ 38,000,000
Level 3
Disclosure of detailed information about financial instruments [line items]
Percentage of increase in copper price	10.00%

Financial instruments and ris_8

Financial instruments and risk management - Summary of notional aluminium forward sales contracts embedded in power contracts (Detail) $ in Millions	Dec. 31, 2020USD ($)t	Dec. 31, 2019USD ($)t
Disclosure of detailed information about financial instruments [line items]
Notional amount (in tonnes) | t	640,963	704,370
Notional amount | $	$ 1,522	$ 1,656
Average hedged rate (in US$ per tonne)	2,375	2,351
Due within 1 year
Disclosure of detailed information about financial instruments [line items]
Notional amount (in tonnes) | t	72,548	65,226
Notional amount | $	$ 159	$ 138
Average hedged rate (in US$ per tonne)	2,189	2,114
Between 1 and 5 years
Disclosure of detailed information about financial instruments [line items]
Notional amount (in tonnes) | t	287,587	286,617
Notional amount | $	$ 663	$ 647
Average hedged rate (in US$ per tonne)	2,305	2,257
Between 5 and 10 years
Disclosure of detailed information about financial instruments [line items]
Notional amount (in tonnes) | t	280,828	352,527
Notional amount | $	$ 701	$ 871
Average hedged rate (in US$ per tonne)	2,495	2,471
After 10 years
Disclosure of detailed information about financial instruments [line items]
Notional amount (in tonnes) | t	0	0
Notional amount | $	$ 0	$ 0
Average hedged rate (in US$ per tonne)	0	0

Financial instruments and ris_9

Financial instruments and risk management - Summary of impact of hedging instrument on statement of financial position (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about financial instruments [line items]
Nominal	$ 1,522	$ 1,656
Carrying amount	134	58
Aluminium embedded derivatives separated from the power contract
Disclosure of detailed information about financial instruments [line items]
Nominal	1,522	1,656
Carrying amount	46	42
Change in fair value in the period	23	29
Embedded derivatives in other financial assets	66	66
Embedded derivatives in other financial liabilities	20	24
Highly Probable Forecast Aluminum Sales
Disclosure of detailed information about financial instruments [line items]
Cash flow hedge reserve	184	196
Change in fair value in the period	(49)	(50)
Highly Probable Forecast Aluminum Sales | Cash flow hedge reserve
Disclosure of detailed information about financial instruments [line items]
Total hedging gain/(loss) recognised reserves	27	36
Hedge ineffectiveness in the period	(4)	(7)
Amount reclassified from reserves to income statement	$ 40	$ 19

Financial instruments and ri_10

Financial instruments and risk management - Summary of changes in market price relevant to alumina purchase price swaps outstanding (Detail) - Commodity price risk - Aluminium - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about financial instruments [line items]
Percentage increase in market price change	10.00%
Percentage decrease in market price change	(10.00%)
Increase in market prices, effect on earnings	$ (19)	$ (28)
Decrease in market prices, effect on earnings	19	27
Increase in market prices, effect on equity	(98)	(97)
Decrease in market prices, effect on equity	$ 100	$ 101

Financial instruments and ri_11

Financial instruments and risk management Financial instruments and risk management - Summary of credit risk (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about financial instruments [line items]
Cash and cash equivalents	$ 10,381	$ 8,027
Trade and other financial receivables	3,286	2,938
Investments in equity accounted units	3,764	3,971
Derivative assets	665	366
Loans to equity accounted units	41	39
Total	17,459	14,383
Credit risk
Disclosure of detailed information about financial instruments [line items]
Cash and cash equivalents	10,381	8,027
Trade and other financial receivables	3,286	2,938
Investments in equity accounted units	2,899	2,839
Derivative assets	665	366
Loans to equity accounted units	41	39
Total	$ 17,272	$ 14,209

Financial instruments and ri_12

Financial instruments and risk management - Summary by currency, Group's net debt, after taking into account relevant cross currency interest rate swaps and foreign exchange contracts (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about financial instruments [line items]
Total borrowings	$ (13,831)	$ (14,115)
Cash and cash equivalents	10,381	8,027
Other investments	2,899	2,839
Net cash/(debt)	(664)	(3,651)	$ 255
Foreign exchange risk
Disclosure of detailed information about financial instruments [line items]
Total borrowings	(12,653)
Lease liabilities	(1,178)
Derivatives related to net debt: designated as hedges	248
Cash and cash equivalents	10,381
Other investments	2,538
Net cash/(debt)	(664)	(3,651)
Foreign exchange risk | US dollar
Disclosure of detailed information about financial instruments [line items]
Total borrowings	(12,102)
Lease liabilities	(342)
Derivatives related to net debt: designated as hedges	248
Cash and cash equivalents	9,517
Other investments	2,538
Net cash/(debt)	(141)	(2,843)
Foreign exchange risk | Australian dollar
Disclosure of detailed information about financial instruments [line items]
Total borrowings	(375)
Lease liabilities	(350)
Derivatives related to net debt: designated as hedges	0
Cash and cash equivalents	439
Other investments	0
Net cash/(debt)	(286)	(561)
Foreign exchange risk | Euro
Disclosure of detailed information about financial instruments [line items]
Total borrowings	(4)
Lease liabilities	(25)
Derivatives related to net debt: designated as hedges	0
Cash and cash equivalents	43
Other investments	0
Net cash/(debt)	14	10
Foreign exchange risk | South African rand
Disclosure of detailed information about financial instruments [line items]
Total borrowings	0
Lease liabilities	(1)
Derivatives related to net debt: designated as hedges	0
Cash and cash equivalents	141
Other investments	0
Net cash/(debt)	140	171
Foreign exchange risk | Canadian dollar
Disclosure of detailed information about financial instruments [line items]
Total borrowings	(170)
Lease liabilities	(199)
Derivatives related to net debt: designated as hedges	0
Cash and cash equivalents	36
Other investments	0
Net cash/(debt)	(333)	(322)
Foreign exchange risk | Other
Disclosure of detailed information about financial instruments [line items]
Total borrowings	(2)
Lease liabilities	(261)
Derivatives related to net debt: designated as hedges	0
Cash and cash equivalents	205
Other investments	0
Net cash/(debt)	$ (58)	$ (106)

Financial instruments and ri_13

Financial instruments and risk management - Foreign exchange risk - Additional information (Detail)	12 Months Ended
	Dec. 31, 2020
Foreign exchange risk
Disclosure of detailed information about financial instruments [line items]
Percentage of change in annual foreign exchange rate	10.00%

Financial instruments and ri_14

Financial instruments and risk management - Gains or Losses Associated with Ten Percent Strengthening of US Dollar (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Disclosure of detailed information about hedging instruments [Line Items]
Effect on net earnings	$ (300)	$ 52	$ 56
Australian dollar
Disclosure of detailed information about hedging instruments [Line Items]
Closing exchange rate	0.77	0.70	0.70
Canadian dollar
Disclosure of detailed information about hedging instruments [Line Items]
Closing exchange rate	0.78	0.77	0.73
Euro
Disclosure of detailed information about hedging instruments [Line Items]
Closing exchange rate	1.23	1.12	1.14
Foreign exchange risk | Australian dollar
Disclosure of detailed information about hedging instruments [Line Items]
Closing exchange rate	77	70
Effect on net earnings	$ 625	$ 453
Amount impacting underlying earnings	(11)	(4)
Impact directly on equity	$ (1,105)	$ (1,002)
Foreign exchange risk | Canadian dollar
Disclosure of detailed information about hedging instruments [Line Items]
Closing exchange rate	78	77
Effect on net earnings	$ (167)	$ (143)
Amount impacting underlying earnings	6	7
Impact directly on equity	$ 0	$ 0
Foreign exchange risk | Euro
Disclosure of detailed information about hedging instruments [Line Items]
Closing exchange rate	123	112
Effect on net earnings	$ 139	$ 178
Amount impacting underlying earnings	3	4
Impact directly on equity	$ 0	$ 0

Financial instruments and ri_15

Financial instruments and risk management - Interest rate risk - Additional information (Detail) € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2020EUR (€)	Dec. 31, 2019EUR (€)
Disclosure of detailed information about financial instruments [line items]
Notional amount	$ 1,522	$ 1,656
Interest rate risk
Disclosure of detailed information about financial instruments [line items]
Adjusted total borrowings	$ 11,700	$ 10,800
Weighted average maturity period	9 years	10 years
Interest rate risk | Sterling
Disclosure of detailed information about financial instruments [line items]
Increase in financial derivative charges on interest rate before tax	$ 68	$ 68
Interest rate risk | US dollar
Disclosure of detailed information about financial instruments [line items]
Increase in financial derivative charges on interest rate before tax	$ 78	$ 78
Interest rate risk | Floating interest rate
Disclosure of detailed information about financial instruments [line items]
Adjusted borrowings, interest rate	86.00%	76.00%	86.00%	76.00%
Interest rate risk | Fixed interest rate
Disclosure of detailed information about financial instruments [line items]
Adjusted borrowings, interest rate	14.00%	24.00%	14.00%	24.00%
Interest rate risk | LIBOR
Disclosure of detailed information about financial instruments [line items]
Borrowing cost recognised	$ 7	$ 20
Borrowings, interest rate basis	1.00%		1.00%
Foreign exchange risk | Fair value hedges
Disclosure of detailed information about financial instruments [line items]
Hedged item, assets	$ 388	151
Hedged item, liabilities	140	298
Alcan Inc. Debentures 7.25% due 2028 | Interest rate swaps
Disclosure of detailed information about financial instruments [line items]
Notional amount	1,500
US Dollar Fixed Rate Borrowings | Interest rate swaps
Disclosure of detailed information about financial instruments [line items]
Notional amount	$ 5,900	$ 4,500	€ 417	€ 818
Effective exchange rate	131.05%		131.05%

Financial instruments and ri_16

Financial instruments and risk management - Summary of Nominal Amount of Bond (Detail) € in Millions, £ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2020EUR (€)	Dec. 31, 2020GBP (£)	Dec. 31, 2019EUR (€)
Disclosure of detailed information about financial instruments [line items]
Notional amount	$ 1,522	$ 1,656
Rio Tinto Finance plc Sterling Bonds 4.0% due 2029 | Interest rate swaps
Disclosure of detailed information about financial instruments [line items]
Notional amount	$ 807			£ 500
Effective exchange rate	161.32%		161.32%	161.32%
US Dollar Fixed Rate Borrowings | Interest rate swaps
Disclosure of detailed information about financial instruments [line items]
Notional amount	$ 5,900	4,500	€ 417		€ 818
Effective exchange rate	131.05%		131.05%	131.05%
Change in fair value of the hedging instrument	$ 7	(24)
Change in fair value of the hedged item	$ (7)	$ 24

Financial instruments and ri_17

Financial instruments and risk management - Summary of borrowings in a hedge relationship (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about financial instruments [line items]
Notional amount	$ 1,522	$ 1,656
Rio Tinto Finance plc Euro Bonds 2.0% due 2020
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	2.00%
Rio Tinto Finance plc Euro Bonds 2.875% due 2024
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	2.875%
Rio Tinto Finance (USA) Limited Bonds 3.75% 2025
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	3.75%
Rio Tinto Finance (USA) Limited Bonds 7.125% 2028
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	7.125%
Alcan Inc. Debentures 7.25% due 2028
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	7.25%
Rio Tinto Finance plc Sterling Bonds 4.0% due 2029
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	4.00%
Alcan Inc. Debentures 7.25% due 2031
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	7.25%
Alcan Inc. Global Notes 6.125% due 2033
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	6.125%
Alcan Inc. Global Notes 5.75% due 2035
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	5.75%
Rio Tinto Finance (USA) Limited Bonds 5.2% 2040
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	5.20%
Rio Tinto Finance (USA) plc Bonds 4.75% 2042
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	4.75%
Rio Tinto Finance (USA) plc Bonds 4.125% 2042
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	4.125%
Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance plc Euro Bonds 2.0% due 2020
Disclosure of detailed information about financial instruments [line items]
Notional amount	$ 526
Carrying Value	0	455
Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance plc Euro Bonds 2.875% due 2024
Disclosure of detailed information about financial instruments [line items]
Notional amount	546
Carrying Value	555	508
Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) Limited Bonds 3.75% 2025
Disclosure of detailed information about financial instruments [line items]
Notional amount	1,200
Carrying Value	1,299	1,229
Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) Limited Bonds 7.125% 2028
Disclosure of detailed information about financial instruments [line items]
Notional amount	750
Carrying Value	1,005	958
Interest rate risk | Borrowings in a Hedge Relationship | Alcan Inc. Debentures 7.25% due 2028
Disclosure of detailed information about financial instruments [line items]
Notional amount	100
Carrying Value	109	104
Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance plc Sterling Bonds 4.0% due 2029
Disclosure of detailed information about financial instruments [line items]
Notional amount	807
Carrying Value	717	647
Interest rate risk | Borrowings in a Hedge Relationship | Alcan Inc. Debentures 7.25% due 2031
Disclosure of detailed information about financial instruments [line items]
Notional amount	400
Carrying Value	438	0
Interest rate risk | Borrowings in a Hedge Relationship | Alcan Inc. Global Notes 6.125% due 2033
Disclosure of detailed information about financial instruments [line items]
Notional amount	750
Carrying Value	744	0
Interest rate risk | Borrowings in a Hedge Relationship | Alcan Inc. Global Notes 5.75% due 2035
Disclosure of detailed information about financial instruments [line items]
Notional amount	300
Carrying Value	292	0
Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) Limited Bonds 5.2% 2040
Disclosure of detailed information about financial instruments [line items]
Notional amount	1,150
Carrying Value	1,173	1,137
Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) plc Bonds 4.75% 2042
Disclosure of detailed information about financial instruments [line items]
Notional amount	500
Carrying Value	501	483
Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) plc Bonds 4.125% 2042
Disclosure of detailed information about financial instruments [line items]
Notional amount	750
Carrying Value	$ 743	$ 716
3 Month LIBOR, plus basis spread | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance plc Euro Bonds 2.0% due 2020
Disclosure of detailed information about financial instruments [line items]
Weighted average interest rate after swaps	1.35%
3 Month LIBOR, plus basis spread | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance plc Euro Bonds 2.875% due 2024
Disclosure of detailed information about financial instruments [line items]
Weighted average interest rate after swaps	1.64%
3 Month LIBOR, plus basis spread | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) Limited Bonds 3.75% 2025
Disclosure of detailed information about financial instruments [line items]
Weighted average interest rate after swaps	1.39%
3 Month LIBOR, plus basis spread | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) Limited Bonds 7.125% 2028
Disclosure of detailed information about financial instruments [line items]
Weighted average interest rate after swaps	3.27%
3 Month LIBOR, plus basis spread | Interest rate risk | Borrowings in a Hedge Relationship | Alcan Inc. Debentures 7.25% due 2028
Disclosure of detailed information about financial instruments [line items]
Weighted average interest rate after swaps	5.43%
3 Month LIBOR, plus basis spread | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance plc Sterling Bonds 4.0% due 2029
Disclosure of detailed information about financial instruments [line items]
Weighted average interest rate after swaps	2.65%
3 Month LIBOR, plus basis spread | Interest rate risk | Borrowings in a Hedge Relationship | Alcan Inc. Debentures 7.25% due 2031
Disclosure of detailed information about financial instruments [line items]
Weighted average interest rate after swaps	5.72%
3 Month LIBOR, plus basis spread | Interest rate risk | Borrowings in a Hedge Relationship | Alcan Inc. Global Notes 6.125% due 2033
Disclosure of detailed information about financial instruments [line items]
Weighted average interest rate after swaps	5.67%
3 Month LIBOR, plus basis spread | Interest rate risk | Borrowings in a Hedge Relationship | Alcan Inc. Global Notes 5.75% due 2035
Disclosure of detailed information about financial instruments [line items]
Weighted average interest rate after swaps	5.18%
3 Month LIBOR, plus basis spread | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) Limited Bonds 5.2% 2040
Disclosure of detailed information about financial instruments [line items]
Weighted average interest rate after swaps	3.79%
3 Month LIBOR, plus basis spread | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) plc Bonds 4.75% 2042
Disclosure of detailed information about financial instruments [line items]
Weighted average interest rate after swaps	3.42%
3 Month LIBOR, plus basis spread | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) plc Bonds 4.125% 2042
Disclosure of detailed information about financial instruments [line items]
Weighted average interest rate after swaps	2.83%
Fixed interest rate | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance plc Euro Bonds 2.0% due 2020
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	2.00%
Fixed interest rate | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance plc Euro Bonds 2.875% due 2024
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	2.875%
Fixed interest rate | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) Limited Bonds 3.75% 2025
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	3.75%
Fixed interest rate | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) Limited Bonds 7.125% 2028
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	7.125%
Fixed interest rate | Interest rate risk | Borrowings in a Hedge Relationship | Alcan Inc. Debentures 7.25% due 2028
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	7.25%
Fixed interest rate | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance plc Sterling Bonds 4.0% due 2029
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	4.00%
Fixed interest rate | Interest rate risk | Borrowings in a Hedge Relationship | Alcan Inc. Debentures 7.25% due 2031
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	7.25%
Fixed interest rate | Interest rate risk | Borrowings in a Hedge Relationship | Alcan Inc. Global Notes 6.125% due 2033
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	6.125%
Fixed interest rate | Interest rate risk | Borrowings in a Hedge Relationship | Alcan Inc. Global Notes 5.75% due 2035
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	5.75%
Fixed interest rate | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) Limited Bonds 5.2% 2040
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	5.20%
Fixed interest rate | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) plc Bonds 4.75% 2042
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	4.75%
Fixed interest rate | Interest rate risk | Borrowings in a Hedge Relationship | Rio Tinto Finance (USA) plc Bonds 4.125% 2042
Disclosure of detailed information about financial instruments [line items]
Borrowings, interest rate	4.125%

Financial instruments and ri_18

Financial instruments and risk management - Summary of derivative financial instruments (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about financial instruments [line items]
Derivative assets	$ 665	$ 366
Derivative financial liabilities	(184)	(351)
Disclosure Of Information About Amounts Recognised In Balance Sheet [Abstract]
Non-current assets	531	308
Current assets	134	58
Current liabilities	(23)	(103)
Non-current liabilities	(161)	(248)
Total net derivative instruments	481	15
Due within 1 year
Disclosure of detailed information about financial instruments [line items]
Derivative assets	134	58
Derivative financial liabilities	(23)	(103)
Between 1 and 5 years
Disclosure of detailed information about financial instruments [line items]
Derivative assets	330	96
Derivative financial liabilities	(14)	(86)
More than 5 years
Disclosure of detailed information about financial instruments [line items]
Derivative assets	201	212
Derivative financial liabilities	(147)	(162)
Other Financial Assets
Disclosure of detailed information about financial instruments [line items]
Total net derivative instruments	481	15
Derivatives designated as hedges
Disclosure of detailed information about financial instruments [line items]
Derivative assets	461	217
Derivative financial liabilities	(160)	(322)
Derivatives designated as hedges | Interest rate swaps
Disclosure of detailed information about financial instruments [line items]
Derivative assets	386	151
Derivative financial liabilities	(1)	(38)
Derivatives designated as hedges | Cross currency interest rate swaps
Disclosure of detailed information about financial instruments [line items]
Derivative assets	2	0
Derivative financial liabilities	(139)	(260)
Derivatives designated as hedges | Aluminium Embedded Derivatives
Disclosure of detailed information about financial instruments [line items]
Derivative assets	66	66
Derivative financial liabilities	(20)	(24)
Derivatives designated as hedges | Currency forward contracts
Disclosure of detailed information about financial instruments [line items]
Derivative assets	7	0
Derivative financial liabilities	0	0
Derivatives not designated as hedges
Disclosure of detailed information about financial instruments [line items]
Derivative assets	204	149
Derivative financial liabilities	(24)	(29)
Derivatives not designated as hedges | Aluminium Embedded Derivatives
Disclosure of detailed information about financial instruments [line items]
Derivative assets	80	96
Derivative financial liabilities	0	0
Derivatives not designated as hedges | Currency forward contracts and swaps
Disclosure of detailed information about financial instruments [line items]
Derivative assets	63	13
Derivative financial liabilities	(1)	(5)
Derivatives not designated as hedges | Other embedded derivatives
Disclosure of detailed information about financial instruments [line items]
Derivative assets	28	14
Derivative financial liabilities	(16)	0
Derivatives not designated as hedges | Other commodity contracts
Disclosure of detailed information about financial instruments [line items]
Derivative assets	33	26
Derivative financial liabilities	$ (7)	$ (24)

Financial instruments and ri_19

Financial instruments and risk management - Summary of fair value of financial instruments (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about borrowings [Line Items]
Borrowings	$ 13,831	$ 14,115
Borrowings excluding overdrafts
Disclosure of detailed information about borrowings [Line Items]
Borrowings	12,653	12,806
Borrowings, fair value	$ 15,076	$ 14,678

Financial instruments and ri_20

Financial instruments and risk management - Fair Values Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about financial instruments [line items]
Borrowings	$ 13,831	$ 14,115
Expected unconditional royalty payments to be received	$ 113	124
Percentage Of Change In Spot Price	15.00%
Level 1
Disclosure of detailed information about financial instruments [line items]
Borrowings at fair value	$ 7,600	7,700
Bonds, fair value	9,500	9,100
Level 3
Disclosure of detailed information about financial instruments [line items]
Borrowings	$ 4,200	4,200
Percentage of change in coal spot price	15.00%
Increase in carrying value of forward contract due to coal spot price assumptions	$ 198	214
Decrease in carrying value of forward contract due to decrease in spot price	46	(57)
Level 3 | Fair value
Disclosure of detailed information about financial instruments [line items]
Borrowings	4,700	4,700
Aluminium embedded derivatives separated from the power contract | Level 3
Disclosure of detailed information about financial instruments [line items]
Long-term embedded derivatives with fair value	$ 126	$ 120

Financial instruments and ri_21

Financial instruments and risk management - Summary of financial instruments carried at fair value (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about financial instruments [line items]
Cash and cash equivalents	$ 10,381	$ 8,027
Investments in equity shares and funds	3,764	3,971
Other investments, including loans	2,899	2,839
Trade and other financial receivables	3,286	2,938
Trade and other financial payables	(5,847)	(5,398)
Net assets	51,903	45,242
Provisionally priced receivables recognised relating to sales contracts	1,671	1,040
Fair value
Disclosure of detailed information about financial instruments [line items]
Cash and cash equivalents	10,381	8,027
Investments in equity shares and funds	75	61
Other investments, including loans	2,899	2,839
Trade and other financial receivables	3,286	2,938
Financial assets (excluding derivative assets)
Forward contracts and option contracts: designated as hedges(f) (Section B)	53	42
Forward contracts and option contracts, not designated as hedges	180	120
Derivatives related to net debt	248	(147)
Trade and other financial payables	(5,847)	(5,398)
Net assets	11,275	8,482
Fair value | Level 1
Disclosure of detailed information about financial instruments [line items]
Cash and cash equivalents	6,411	5,320
Investments in equity shares and funds	35	26
Other investments, including loans	2,563	2,607
Trade and other financial receivables	5	15
Financial assets (excluding derivative assets)
Forward contracts and option contracts: designated as hedges(f) (Section B)	0	0
Forward contracts and option contracts, not designated as hedges	0	0
Derivatives related to net debt	0	0
Trade and other financial payables	0	0
Net assets	9,014	7,968
Fair value | Level 2
Disclosure of detailed information about financial instruments [line items]
Investments in equity shares and funds	0	0
Other investments, including loans	0	0
Trade and other financial receivables	1,802	1,122
Financial assets (excluding derivative assets)
Forward contracts and option contracts: designated as hedges(f) (Section B)	7	0
Forward contracts and option contracts, not designated as hedges	69	25
Derivatives related to net debt	248	(147)
Trade and other financial payables	(30)	(57)
Net assets	2,096	943
Fair value | Level 3
Disclosure of detailed information about financial instruments [line items]
Investments in equity shares and funds	40	35
Other investments, including loans	198	211
Trade and other financial receivables	0	0
Financial assets (excluding derivative assets)
Forward contracts and option contracts: designated as hedges(f) (Section B)	46	42
Forward contracts and option contracts, not designated as hedges	111	95
Derivatives related to net debt	0	0
Trade and other financial payables	0	0
Net assets	395	383
Not held at fair value
Disclosure of detailed information about financial instruments [line items]
Cash and cash equivalents	3,970	2,707
Investments in equity shares and funds	0	0
Other investments, including loans	138	21
Trade and other financial receivables	1,479	1,801
Financial assets (excluding derivative assets)
Forward contracts and option contracts: designated as hedges(f) (Section B)	0	0
Forward contracts and option contracts, not designated as hedges	0	0
Derivatives related to net debt	0	0
Trade and other financial payables	(5,817)	(5,341)
Net assets	$ (230)	$ (812)

Financial instruments and ri_22

Financial instruments and risk management - Summary of changes in fair value of Level 3 financial assets and financial liabilities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about financial instruments [line items]
Currency translation adjustments	$ 890	$ 65
Level 3
Disclosure of detailed information about financial instruments [line items]
Opening balance	383	637
Currency translation adjustments	16	(1)
Total realised losses included in consolidated sales revenue	11	0
Total realised losses included in net operating costs	(39)	(7)
Total unrealised (losses)/gains included in net operating costs	24	(254)
Total unrealised gains transferred into other comprehensive income through cash flow hedges	26	28
Additions	1	1
Disposals/maturity of financial instruments	(27)	(21)
Closing balance	395	383
Net losses for the year included in the income statement for assets and liabilities held at year end(a)	$ 0	$ (263)

Contingencies and commitments -

Contingencies and commitments - Summary of capital commitments (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of commitments and contingencies [Line Items]
Capital commitments	$ 3,152	$ 4,053
Joint ventures
Disclosure of commitments and contingencies [Line Items]
Capital commitments	9	93
Due within 1 year
Disclosure of commitments and contingencies [Line Items]
Capital commitments	3,021	3,069
Due within 1 year | Joint ventures
Disclosure of commitments and contingencies [Line Items]
Capital commitments	9	92
Between 1 and 3 years
Disclosure of commitments and contingencies [Line Items]
Capital commitments	97	851
Between 1 and 3 years | Joint ventures
Disclosure of commitments and contingencies [Line Items]
Capital commitments	0	1
Between 3 and 5 years
Disclosure of commitments and contingencies [Line Items]
Capital commitments	0	133
More than 5 years
Disclosure of commitments and contingencies [Line Items]
Capital commitments	$ 34	$ 0

Contingencies and commitments_2

Contingencies and commitments - Additional information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of commitments and contingencies [Line Items]
Contractual capital commitments	$ 1,500	$ 900
Borrowings	$ 13,831	14,115
Turquoise Hill Resources Ltd(including Oyu Tolgoi LLC)
Disclosure of commitments and contingencies [Line Items]
Group interest (%)	50.80%
Oyu Tolgoi
Disclosure of commitments and contingencies [Line Items]
Borrowings	$ 4,300	4,300
Erdenes Oyu Tolgoi LLC
Disclosure of commitments and contingencies [Line Items]
Group interest (%)	34.00%
Turquoise Hill Resources Ltd
Disclosure of commitments and contingencies [Line Items]
Group interest (%)	66.00%
Minera Escondida Limitada
Disclosure of commitments and contingencies [Line Items]
Minera Escondida Limitada undrawn shareholder line of credit Rio Tinto share	$ 225	225
Group interest (%)	30.00%
Rio Tinto Finance (USA) Limited and Rio Tinto Finance (USA) plc | Contingent liabilities related to joint ventures
Disclosure of commitments and contingencies [Line Items]
Contractual payments	$ 10.5
Rio Tinto Finance (USA) Limited and Rio Tinto Finance (USA) plc | Contingent liabilities related to joint ventures | Financial guarantee contracts
Disclosure of commitments and contingencies [Line Items]
Amounts guaranteed by parent companies	7,500	7,500
Rio Tinto Finance (USA) Limited and Rio Tinto Finance (USA) plc | Contingent liabilities related to joint ventures | Financial guarantee contracts | Bonds
Disclosure of commitments and contingencies [Line Items]
Amounts guaranteed by parent companies	4,400	4,400
Rio Tinto Finance (USA) Limited and Rio Tinto Finance (USA) plc | Contingent liabilities related to joint ventures | Financial guarantee contracts | Bonds
Disclosure of commitments and contingencies [Line Items]
Amounts guaranteed by parent companies	$ 1,200	$ 1,600

Contingencies and commitments_3

Contingencies and commitments - Summary of aggregate amount of future payment commitments under purchase obligations outstanding (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of future payment commitments under purchase obligations [Line Items]
Aggregate amount of future payment commitments under purchase obligations outstanding	$ 16,633	$ 16,919
Due within 1 year
Disclosure of future payment commitments under purchase obligations [Line Items]
Aggregate amount of future payment commitments under purchase obligations outstanding	3,100	2,920
Between 1 and 2 years
Disclosure of future payment commitments under purchase obligations [Line Items]
Aggregate amount of future payment commitments under purchase obligations outstanding	1,715	1,705
Between 2 and 3 years
Disclosure of future payment commitments under purchase obligations [Line Items]
Aggregate amount of future payment commitments under purchase obligations outstanding	1,291	1,431
Between 3 and 4 years
Disclosure of future payment commitments under purchase obligations [Line Items]
Aggregate amount of future payment commitments under purchase obligations outstanding	1,242	1,084
Between 4 and 5 years
Disclosure of future payment commitments under purchase obligations [Line Items]
Aggregate amount of future payment commitments under purchase obligations outstanding	848	1,082
More than 5 years
Disclosure of future payment commitments under purchase obligations [Line Items]
Aggregate amount of future payment commitments under purchase obligations outstanding	$ 8,437	$ 8,697

Contingencies and commitments_4

Contingencies and commitments - Summary of subsidiaries and joint operations contingent liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of contingent liabilities [abstract]
Indemnities and other performance guarantees	$ 146	$ 204

Average number of employees - S

Average number of employees - Summary of average number of employees (Detail) - Employee	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of average number of employees [Line Items]
Average number of employees	47,474	46,007	47,458
Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	3,141	3,139	3,129
Australia and New Zealand
Disclosure of average number of employees [Line Items]
Average number of employees	21,116	19,814	19,595
Australia and New Zealand | Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	634	619	578
Canada
Disclosure of average number of employees [Line Items]
Average number of employees	11,814	11,576	10,620
Canada | Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	0	0	0
UK
Disclosure of average number of employees [Line Items]
Average number of employees	172	190	287
UK | Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	0	0	0
Europe
Disclosure of average number of employees [Line Items]
Average number of employees	1,020	959	1,418
Europe | Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	0	0	0
Africa
Disclosure of average number of employees [Line Items]
Average number of employees	3,773	4,371	4,758
Africa | Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	1,214	1,250	1,262
United States of America
Disclosure of average number of employees [Line Items]
Average number of employees	3,543	3,400	3,792
United States of America | Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	0	0	0
Mongolia
Disclosure of average number of employees [Line Items]
Average number of employees	3,465	3,215	2,886
Mongolia | Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	0	0	0
Indonesia
Disclosure of average number of employees [Line Items]
Average number of employees	0	0	1,615
Indonesia | Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	0	0	0
South America
Disclosure of average number of employees [Line Items]
Average number of employees	1,513	1,513	1,499
South America | Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	1,293	1,270	1,289
India
Disclosure of average number of employees [Line Items]
Average number of employees	324	272	288
India | Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	0	0	0
Singapore
Disclosure of average number of employees [Line Items]
Average number of employees	456	430	422
Singapore | Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	0	0	0
Other countries
Disclosure of average number of employees [Line Items]
Average number of employees	278	267	278
Other countries | Investment in equity accounted units
Disclosure of average number of employees [Line Items]
Average number of employees	0	0	0
Subsidiaries and joint operations
Disclosure of average number of employees [Line Items]
Average number of employees	44,333	42,868	44,329
Percent of employees of subsidiary companies	100.00%
Subsidiaries and joint operations | Australia and New Zealand
Disclosure of average number of employees [Line Items]
Average number of employees	20,482	19,195	19,017
Subsidiaries and joint operations | Canada
Disclosure of average number of employees [Line Items]
Average number of employees	11,814	11,576	10,620
Subsidiaries and joint operations | UK
Disclosure of average number of employees [Line Items]
Average number of employees	172	190	287
Subsidiaries and joint operations | Europe
Disclosure of average number of employees [Line Items]
Average number of employees	1,020	959	1,418
Subsidiaries and joint operations | Africa
Disclosure of average number of employees [Line Items]
Average number of employees	2,559	3,121	3,496
Subsidiaries and joint operations | United States of America
Disclosure of average number of employees [Line Items]
Average number of employees	3,543	3,400	3,792
Subsidiaries and joint operations | Mongolia
Disclosure of average number of employees [Line Items]
Average number of employees	3,465	3,215	2,886
Subsidiaries and joint operations | Indonesia
Disclosure of average number of employees [Line Items]
Average number of employees	0	0	1,615
Subsidiaries and joint operations | South America
Disclosure of average number of employees [Line Items]
Average number of employees	220	243	210
Subsidiaries and joint operations | India
Disclosure of average number of employees [Line Items]
Average number of employees	324	272	288
Subsidiaries and joint operations | Singapore
Disclosure of average number of employees [Line Items]
Average number of employees	456	430	422
Subsidiaries and joint operations | Other countries
Disclosure of average number of employees [Line Items]
Average number of employees	278	267	278

Principal subsidiaries Princi_2

Principal subsidiaries Principal subsidiaries - Principal in subsidiaries (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of subsidiaries [line items]
Proportion of net beneficial interest	53.00%
Oyu Tolgoi
Disclosure of subsidiaries [line items]
Proportion of indirect ownership interest in subsidiary	33.50%
Robe River
Disclosure of subsidiaries [line items]
Group interest (%)	65.00%
Non-controlling interest (%)	12.00%
Proportion of net beneficial interest	53.00%
Consrcio De Alumnio Do Maranho
Disclosure of subsidiaries [line items]
Proportion of ownership interest in joint venture	10.00%
Diavik
Disclosure of subsidiaries [line items]
Group interest (%)		60.00%
Proportion of ownership interest in joint venture	60.00%
Proportion receivable or contingent asset percent	40.00%
Argyle Diamonds Limited
Disclosure of subsidiaries [line items]
Group interest (%)		100.00%
Argyle Diamonds Limited | Ordinary
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%
Dampier Salt Limited | Ordinary
Disclosure of subsidiaries [line items]
Proportion of class held (%)	68.36%
Group interest (%)	68.36%
Non-controlling interest (%)	31.64%
Energy Resources of Australia Ltd | Ordinary
Disclosure of subsidiaries [line items]
Proportion of class held (%)	86.33%
Group interest (%)	86.33%	68.60%
Non-controlling interest (%)	13.67%
Hamersley Iron Pty Limited
Disclosure of subsidiaries [line items]
Group interest (%)	100.00%
Hamersley Iron Pty Limited | Ordinary
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%
North Mining Limited | Robe River
Disclosure of subsidiaries [line items]
Non-controlling interest (%)	35.00%
North Mining Limited | Ordinary
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%
Rio Tinto Aluminium (Holdings) Limited | Ordinary
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%
Robe River Mining Co Pty Ltd
Disclosure of subsidiaries [line items]
Group interest (%)	60.00%
Robe River Mining Co Pty Ltd | Robe River
Disclosure of subsidiaries [line items]
Non-controlling interest (%)	30.00%
Robe River Mining Co Pty Ltd | Class A and Class B Shares
Disclosure of subsidiaries [line items]
Group interest (%)	60.00%
Non-controlling interest (%)	40.00%
Robe River Mining Co Pty Ltd | Class A
Disclosure of subsidiaries [line items]
Proportion of class held (%)	40.00%
Robe River Mining Co Pty Ltd | Class A
Disclosure of subsidiaries [line items]
Proportion of class held (%)	76.36%
Alcan Alumina Ltda. | Quota
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%
Iron Ore Company of Canada | Common
Disclosure of subsidiaries [line items]
Proportion of class held (%)	58.72%
Group interest (%)	58.72%
Non-controlling interest (%)	41.28%
Rio Tinto Fer et Titane Inc.
Disclosure of subsidiaries [line items]
Group interest (%)		100.00%
Rio Tinto Fer et Titane Inc. | Common
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%
Rio Tinto Fer et Titane Inc. | Class B preference
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%
Rio Tinto Fer et Titane Inc. | CAD 0.01 preferred
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%
Rio Tinto Alcan Inc. | Common
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%
Diavik Diamond Mines (2012) Inc. | Common
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%
Simfer Jersey Limited | Ordinary
Disclosure of subsidiaries [line items]
Proportion of class held (%)	53.00%
Group interest (%)	53.00%	53.00%
Non-controlling interest (%)	47.00%
Simfer S.A.
Disclosure of subsidiaries [line items]
Group interest (%)	85.00%	85.00%
Non-controlling interest (%)		45.05%
Proportion of indirect ownership interest in subsidiary	45.05%
QIT Madagascar Minerals SA
Disclosure of subsidiaries [line items]
Group interest (%)		80.00%
Portion of additional economic interest held through non voting investment	5.00%
Portion of economic interest held through non voting investment	85.00%
Proportion of voting rights held by non-controlling interests	20.00%
QIT Madagascar Minerals SA | Common
Disclosure of subsidiaries [line items]
Proportion of class held (%)	80.00%
Group interest (%)	80.00%
QIT Madagascar Minerals SA | Common Shares And Investment Certificates
Disclosure of subsidiaries [line items]
Non-controlling interest (%)	15.00%
QIT Madagascar Minerals SA | Investment certificates
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%
QIT Madagascar Minerals SA | Voting certificates
Disclosure of subsidiaries [line items]
Proportion of class held (%)	80.00%
Group interest (%)	80.00%
Non-controlling interest (%)	20.00%
Turquoise Hill Resources Ltd
Disclosure of subsidiaries [line items]
Group interest (%)	50.79%
Turquoise Hill Resources Ltd | Oyu Tolgoi
Disclosure of subsidiaries [line items]
Group interest (%)	66.00%
Turquoise Hill Resources Ltd(including Oyu Tolgoi LLC)
Disclosure of subsidiaries [line items]
Group interest (%)	50.80%
Turquoise Hill Resources Ltd(including Oyu Tolgoi LLC) | Common
Disclosure of subsidiaries [line items]
Proportion of class held (%)	50.79%
Group interest (%)	50.79%
Non-controlling interest (%)	49.21%
Richards Bay Titanium (Proprietary) Limited | B Ordinary, B Preference, and Parent Preference
Disclosure of subsidiaries [line items]
Group interest (%)	74.00%
Non-controlling interest (%)	26.00%
Richards Bay Titanium (Proprietary) Limited | B Ordinary
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Richards Bay Titanium (Proprietary) Limited | B preference
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Richards Bay Titanium (Proprietary) Limited | Parent Preference
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Richards Bay Mining (Proprietary) Limited | B Ordinary, B Preference, and Parent Preference
Disclosure of subsidiaries [line items]
Group interest (%)	74.00%
Non-controlling interest (%)	26.00%
Richards Bay Mining (Proprietary) Limited | B Ordinary
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Richards Bay Mining (Proprietary) Limited | B preference
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Richards Bay Mining (Proprietary) Limited | Parent Preference
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Kennecott Holdings Corporation (including Kennecott Utah Copper and Kennecott Exploration) | Common
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%
U.S. Borax Inc. | Common
Disclosure of subsidiaries [line items]
Proportion of class held (%)	100.00%
Group interest (%)	100.00%

Principal subsidiaries - Subsid

Principal subsidiaries - Subsidiaries financial information (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of subsidiaries [line items]
Consolidated sales revenue		$ 44,611	$ 43,165	$ 40,522
Profit after tax for the year		10,400	6,972	13,925
Profit/(loss) after tax – attributable to non-controlling interests		631	(1,038)	287
Profit/(loss) after tax – attributable to owners of Rio Tinto		9,769	8,010	13,638
Other comprehensive income/(loss)		2,584	346	(3,139)
Total comprehensive income/(loss)	[1]	12,984	7,318	10,786
Non-current assets		76,535	70,499
Current assets		20,855	17,303
Non-current liabilities		(33,880)	(31,435)
Net assets/(liabilities)		51,903	45,242
Attributable to non-controlling interests		4,849	4,710
Equity attributable to owners of Rio Tinto		47,054	40,532	43,686
Cash flow from operations		15,875	14,912	11,821
Dividends paid to holders of non-controlling interests in subsidiaries		(683)	(376)	(420)
Borrowings		13,831	14,115
Goodwill		946	922	$ 912
Iron Ore Company of Canada
Disclosure of subsidiaries [line items]
Consolidated sales revenue		2,269	2,014
Profit after tax for the year		611	543
Profit/(loss) after tax – attributable to non-controlling interests		252	224
Profit/(loss) after tax – attributable to owners of Rio Tinto		359	319
Other comprehensive income/(loss)		56	57
Total comprehensive income/(loss)		667	600
Non-current assets		2,733	2,585
Current assets		670	610
Current liabilities		(462)	(532)
Non-current liabilities		(993)	(927)
Net assets/(liabilities)		1,948	1,736
Attributable to non-controlling interests		804	718
Equity attributable to owners of Rio Tinto		1,144	1,018
Cash flow from operations		1,027	1,039
Dividends paid to holders of non-controlling interests in subsidiaries		(180)	(228)
Energy Resources of Australia
Disclosure of subsidiaries [line items]
Consolidated sales revenue		162	145
Profit after tax for the year		9	5
Profit/(loss) after tax – attributable to non-controlling interests		3	2
Profit/(loss) after tax – attributable to owners of Rio Tinto		5	3
Other comprehensive income/(loss)		20	2
Total comprehensive income/(loss)		29	7
Non-current assets		329	76
Current assets		371	258
Current liabilities		(176)	(127)
Non-current liabilities		(427)	(462)
Net assets/(liabilities)		97	(255)
Attributable to non-controlling interests		18	0
Equity attributable to owners of Rio Tinto		79	(255)
Cash flow from operations		(15)	(73)
Dividends paid to holders of non-controlling interests in subsidiaries		0	0
Turquoise Hill
Disclosure of subsidiaries [line items]
Consolidated sales revenue		1,078	1,166
Profit after tax for the year		357	(2,137)
Profit/(loss) after tax – attributable to non-controlling interests		130	(1,490)
Profit/(loss) after tax – attributable to owners of Rio Tinto		227	(647)
Other comprehensive income/(loss)		2	0
Total comprehensive income/(loss)		359	(2,137)
Non-current assets		10,930	9,589
Current assets		1,496	2,449
Current liabilities		(540)	(493)
Non-current liabilities		(4,404)	(4,405)
Net assets/(liabilities)		7,482	7,140
Attributable to non-controlling interests		2,424	2,369
Equity attributable to owners of Rio Tinto		5,058	4,771
Cash flow from operations		380	298
Dividends paid to holders of non-controlling interests in subsidiaries		0	0
Robe River Mining Co Pty Ltd
Disclosure of subsidiaries [line items]
Consolidated sales revenue		1,738	1,493
Profit after tax for the year		939	808
Profit/(loss) after tax – attributable to non-controlling interests		376	312
Profit/(loss) after tax – attributable to owners of Rio Tinto		563	496
Other comprehensive income/(loss)		294	(13)
Total comprehensive income/(loss)		1,233	795
Non-current assets		3,452	2,622
Current assets		865	1,161
Current liabilities		(380)	(173)
Non-current liabilities		(255)	(84)
Net assets/(liabilities)		3,682	3,526
Attributable to non-controlling interests		1,397	1,404
Equity attributable to owners of Rio Tinto		2,285	2,122
Cash flow from operations		1,491	1,255
Dividends paid to holders of non-controlling interests in subsidiaries		(332)	(139)
Other Companies And Eliminations
Disclosure of subsidiaries [line items]
Consolidated sales revenue		2,028	1,743
Profit after tax for the year		1,019	825
Profit/(loss) after tax – attributable to non-controlling interests		0	0
Profit/(loss) after tax – attributable to owners of Rio Tinto		1,019	825
Other comprehensive income/(loss)		136	(12)
Total comprehensive income/(loss)		1,155	813
Non-current assets		4,247	3,687
Current assets		2,239	1,873
Current liabilities		(414)	(303)
Non-current liabilities		(4,752)	(3,392)
Net assets/(liabilities)		1,320	1,865
Attributable to non-controlling interests		0	0
Equity attributable to owners of Rio Tinto		1,320	1,865
Cash flow from operations		1,771	1,447
Dividends paid to holders of non-controlling interests in subsidiaries		(165)	0
Robe River
Disclosure of subsidiaries [line items]
Consolidated sales revenue		3,766	3,236
Profit after tax for the year		1,958	1,633
Profit/(loss) after tax – attributable to non-controlling interests		376	312
Profit/(loss) after tax – attributable to owners of Rio Tinto		1,582	1,321
Other comprehensive income/(loss)		430	(25)
Total comprehensive income/(loss)		2,388	1,608
Non-current assets		7,699	6,309
Current assets		3,104	3,034
Current liabilities		(794)	(476)
Non-current liabilities		(5,007)	(3,476)
Net assets/(liabilities)		5,002	5,391
Attributable to non-controlling interests		1,397	1,404
Equity attributable to owners of Rio Tinto		3,605	3,987
Cash flow from operations		3,262	2,702
Dividends paid to holders of non-controlling interests in subsidiaries		(497)	(139)
North Mining Limited | Robe River
Disclosure of subsidiaries [line items]
Goodwill		383	349
Amended and Restated Shareholders Agreement | Erdenes Oyu Tolgoi LLC
Disclosure of subsidiaries [line items]
Borrowings		1,378	1,241
Interest receivable		$ 804	$ 655
Floating interest rate | Erdenes Oyu Tolgoi LLC
Disclosure of subsidiaries [line items]
Borrowings, interest rate basis		6.50%
Floating interest rate | Amended and Restated Shareholders Agreement | Erdenes Oyu Tolgoi LLC
Disclosure of subsidiaries [line items]
Borrowings, interest rate basis		6.50%
[1]	Refer to Group statement of comprehensive income for further details. Adjustments to other reserves include currency translation attributable to owners of Rio Tinto, other than that arising on Rio Tinto Limited’s share capital.

Principal joint operations - Su

Principal joint operations - Summary of principle joint operations (Detail)	12 Months Ended
	Dec. 31, 2020
Tomago Aluminium Joint Venture
Disclosure of joint operations [line items]
Principal activities, Joint Operation	Aluminium smelting
Group interest (%), Joint Operation	51.60%
Country of incorporation, Joint Operation	Australia
Company of operation, Joint Operation	Tomago Aluminium Joint Venture
Gladstone Power Station
Disclosure of joint operations [line items]
Principal activities, Joint Operation	Power generation
Group interest (%), Joint Operation	42.10%
Country of incorporation, Joint Operation	Australia
Company of operation, Joint Operation	Gladstone Power Station
Hope Downs Joint Venture
Disclosure of joint operations [line items]
Principal activities, Joint Operation	Iron ore mining
Group interest (%), Joint Operation	50.00%
Country of incorporation, Joint Operation	Australia
Company of operation, Joint Operation	Hope Downs Joint Venture
Queensland Alumina Limited
Disclosure of joint operations [line items]
Principal activities, Joint Operation	Alumina production
Group interest (%), Joint Operation	80.00%
Country of incorporation, Joint Operation	Australia
Company of operation, Joint Operation	Queensland Alumina Limited
Pilbara Iron Arrangements
Disclosure of joint operations [line items]
Principal activities, Joint Operation	Infrastructure, corporate and mining services
Country of incorporation, Joint Operation	Australia
Company of operation, Joint Operation	Pilbara Iron arrangement
New Zealand Aluminium Smelters Limited
Disclosure of joint operations [line items]
Principal activities, Joint Operation	Aluminium smelting
Group interest (%), Joint Operation	79.40%
Country of incorporation, Joint Operation	New Zealand
Company of operation, Joint Operation	New Zealand Aluminium Smelters Limited
Aluminerie Alouette Inc.
Disclosure of joint operations [line items]
Principal activities, Joint Operation	Aluminium production
Group interest (%), Joint Operation	40.00%
Country of incorporation, Joint Operation	Canada
Company of operation, Joint Operation	Aluminerie Alouette Inc.
Pechiney Reynolds Quebec Inc
Disclosure of joint operations [line items]
Principal activities, Joint Operation	Aluminium smelting
Group interest (%), Joint Operation	50.20%
Country of incorporation, Joint Operation	United States of America
Company of operation, Joint Operation	Pechiney Reynolds Quebec Inc

Principal joint operations - _2

Principal joint operations - Summary of principle joint operations (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2020Subsidiary
New Zealand Aluminium Smelters Limited
Disclosure of joint operations [line items]
Group interest (%), Joint Operation	79.40%
Principal activities, Joint Operation	Aluminium smelting
Queensland Alumina Limited
Disclosure of joint operations [line items]
Group interest (%), Joint Operation	80.00%
Principal activities, Joint Operation	Alumina production
Pilbara Iron Arrangements
Disclosure of joint operations [line items]
Number of subsidiary	2
Company of operation, Subsidiary	Pilbara Iron (Company) Services Pty Ltd and Pilbara Iron Pty Ltd.
Principal activities, Joint Operation	Infrastructure, corporate and mining services
Pechiney Reynolds Quebec Inc
Disclosure of joint operations [line items]
Group interest (%), Joint Operation	50.20%
Principal activities, Joint Operation	Aluminium smelting
Pechiney Reynolds Quebec Inc | Aluminerie De Becancour Inc
Disclosure of joint operations [line items]
Group interest (%)	50.10%
Company of operation	Aluminerie de Bécancour, Inc.
Principal activities, Joint Operation	aluminium smelter

Principal joint ventures - Summ

Principal joint ventures - Summary of joint ventures (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of joint ventures [line items]
Number of shares held (in shares)	0	0	0
Minera Escondida Limitada
Disclosure of joint ventures [line items]
Group interest (%)	30.00%
Sohar
Disclosure of joint ventures [line items]
Group interest (%)	20.00%
Sohar | Ordinary
Disclosure of joint ventures [line items]
Number of shares held (in shares)	37,500
Proportion of class held (%)	20.00%
Group interest (%)	20.00%

Principal joint ventures - Su_2

Principal joint ventures - Summary of joint ventures (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2020
Minera Escondida Limitada
Disclosure of joint ventures [line items]
Group interest (%)	30.00%
Minera Escondida Limitada | BHP Billiton
Disclosure of joint ventures [line items]
Group interest (%)	57.50%
Sohar
Disclosure of joint ventures [line items]
Group interest (%)	20.00%

Principal joint ventures - Su_3

Principal joint ventures - Summary financial information for joint ventures by fair value (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of joint ventures [line items]
Consolidated sales revenue		$ 44,611	$ 43,165	$ 40,522
Depreciation and amortisation		(4,279)	(4,384)	(4,015)
Finance costs		(268)	(554)	(552)
Taxation		(4,991)	(4,147)	(4,242)
Profit after tax for the year		10,400	6,972	13,925
Other comprehensive income/(loss)		2,584	346	(3,139)
Total comprehensive income/(loss)	[1]	12,984	7,318	$ 10,786
Non-current assets		76,535	70,499
Current assets		20,855	17,303
Non-current liabilities		(33,880)	(31,435)
Net assets		51,903	45,242
Cash and cash equivalents		10,381	8,027
Minera Escondida Limitada
Disclosure of joint ventures [line items]
Consolidated sales revenue		7,650	7,120
Depreciation and amortisation		(1,427)	(1,693)
Impairment charges		0	0
Other operating costs		(2,756)	(3,670)
Operating profit/(loss)		3,467	1,757
Finance costs		(137)	(157)
Taxation		(1,197)	(627)
Profit after tax for the year		2,133	973
Other comprehensive income/(loss)		(40)	(17)
Total comprehensive income/(loss)		2,093	956
Non-current assets		11,833	12,450
Current assets		3,107	2,250
Current liabilities		(1,813)	(1,827)
Non-current liabilities		(4,560)	(4,670)
Net assets		8,567	8,203
Cash and cash equivalents		1,103	603
– current financial liabilities		(790)	(807)
– non-current financial liabilities		(2,560)	(2,380)
Dividends received from joint venture (Rio Tinto share)		585	666
Sohar
Disclosure of joint ventures [line items]
Consolidated sales revenue		640	715
Depreciation and amortisation		(115)	(115)
Impairment charges		(1,100)	0
Other operating costs		(430)	(505)
Operating profit/(loss)		(1,005)	95
Finance costs		(20)	(35)
Taxation		(15)	(10)
Profit after tax for the year		(1,040)	50
Other comprehensive income/(loss)		0	0
Total comprehensive income/(loss)		(1,040)	50
Non-current assets		1,850	3,045
Current assets		270	290
Current liabilities		(675)	(205)
Non-current liabilities		(200)	(845)
Net assets		1,245	2,285
Cash and cash equivalents		30	20
– current financial liabilities		(565)	(110)
– non-current financial liabilities		(30)	(675)
Dividends received from joint venture (Rio Tinto share)		$ 0	$ 0
[1]	Refer to Group statement of comprehensive income for further details. Adjustments to other reserves include currency translation attributable to owners of Rio Tinto, other than that arising on Rio Tinto Limited’s share capital.

Principal joint ventures - Reco

Principal joint ventures - Reconciliation of financial information for joint ventures by carrying value (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of joint ventures [line items]
Net assets/(liabilities)	$ 51,903	$ 45,242
Minera Escondida Limitada
Disclosure of joint ventures [line items]
Net assets/(liabilities)	8,567	8,203
Group's ownership interest	2,570	2,461
Carrying value of Group's interest	2,570	2,461
Sohar
Disclosure of joint ventures [line items]
Net assets/(liabilities)	1,245	2,285
Group's ownership interest	249	457
Carrying value of Group's interest	$ 249	$ 457

Principal joint ventures - Re_2

Principal joint ventures - Reconciliation of financial information for joint ventures by carrying value (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disclosure of joint ventures [line items]
Deferred tax liabilities	$ 3,239	$ 3,220
Investment in equity accounted units
Disclosure of joint ventures [line items]
Deferred tax liabilities	$ 358	$ 362

Principal associates - Summary

Principal associates - Summary of principal associates (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of associates [Line Items]
Rio Tinto Limited shares were held by Rio Tinto plc	0	0	0
Boyne Smelters Limited | Ordinary
Disclosure of associates [Line Items]
Company of operation, Associate	Boyne Smelters Limited
Rio Tinto Limited shares were held by Rio Tinto plc	153,679,560
Proportion of class held (%), Associate	59.40%
Group interest (%), Associate	59.40%
Mineracao Rio do Norte S.A.
Disclosure of associates [Line Items]
Group interest (%), Associate	12.00%
Mineracao Rio do Norte S.A. | Ordinary
Disclosure of associates [Line Items]
Rio Tinto Limited shares were held by Rio Tinto plc	25,000,000,000
Proportion of class held (%), Associate	12.50%
Mineracao Rio do Norte S.A. | Preferred Shares
Disclosure of associates [Line Items]
Company of operation, Associate	Mineracao Rio do Norte S.A.
Rio Tinto Limited shares were held by Rio Tinto plc	47,000,000,000
Proportion of class held (%), Associate	11.75%
Mineracao Rio do Norte S.A. | Common and preferred shares
Disclosure of associates [Line Items]
Group interest (%), Associate	12.00%
Halco Mining Inc
Disclosure of associates [Line Items]
Group interest (%), Associate	51.00%
Halco Mining Inc | Common
Disclosure of associates [Line Items]
Company of operation, Associate	Halco (Mining) Inc
Rio Tinto Limited shares were held by Rio Tinto plc	4,500
Proportion of class held (%), Associate	45.00%
Group interest (%), Associate	45.00%

Principal associates - Summar_2

Principal associates - Summary of principal associates (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2020
Mineracao Rio do Norte S.A.
Disclosure of associates [Line Items]
Group interest (%), Associate	12.00%
Halco Mining Inc
Disclosure of associates [Line Items]
Group interest (%), Associate	51.00%
Halco Mining Inc | Compagnie des Bauxites de Guine
Disclosure of associates [Line Items]
Company of operation, Subsidiary	Compagnie des Bauxites de Guinée
Country of incorporation, Subsidiary	Guinea

Principal associates - Addition

Principal associates - Additional information (Detail)	12 Months Ended
	Dec. 31, 2020
Disclosure of associates [abstract]
Description of basis of preparation of summarised financial information of associate	100

Principal associates - Reconcil

Principal associates - Reconciliation of financial information for principal associates by carrying value (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of associates [Line Items]
Consolidated sales revenue		$ 44,611	$ 43,165	$ 40,522
(Loss)/profit after tax		10,400	6,972	13,925
Other comprehensive income/(loss)		2,584	346	(3,139)
Total comprehensive income/(loss)	[1]	12,984	7,318	10,786
Non-current assets		76,535	70,499
Current assets		20,855	17,303
Non-current liabilities		(33,880)	(31,435)
Net assets/(liabilities)		51,903	45,242
Loans to equity accounted units		112	113
Impairment loss recognised in profit or loss		904	3,487	$ 132
Boyne Smelters Limited
Disclosure of associates [Line Items]
Consolidated sales revenue		0	0
(Loss)/profit after tax		(198)	(7)
Other comprehensive income/(loss)		30	(3)
Total comprehensive income/(loss)		(168)	(10)
Non-current assets		1,037	1,229
Current assets		98	96
Current liabilities		(146)	(114)
Non-current liabilities		(779)	(814)
Net assets/(liabilities)		210	397
Group's ownership interest		125	236
Loans to equity accounted units		112	113
Carrying value of Group's interest		237	$ 349
Impairment loss recognised in profit or loss		$ 200
[1]	Refer to Group statement of comprehensive income for further details. Adjustments to other reserves include currency translation attributable to owners of Rio Tinto, other than that arising on Rio Tinto Limited’s share capital.

Principal associates - Summar_3

Principal associates - Summary information for joint ventures and associates that are not individually material to the group (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of associates [Line Items]
(Loss)/profit after tax		$ 10,400	$ 6,972	$ 13,925
Other comprehensive income		2,584	346	(3,139)
Total comprehensive income/(loss)	[1]	12,984	7,318	$ 10,786
Associates
Disclosure of associates [Line Items]
Carrying value of Group's interest		708	704
(Loss)/profit after tax		0	3
Other comprehensive income		(5)	10
Total comprehensive income/(loss)		$ (5)	$ 13
[1]	Refer to Group statement of comprehensive income for further details. Adjustments to other reserves include currency translation attributable to owners of Rio Tinto, other than that arising on Rio Tinto Limited’s share capital.

Purchases and sales of subsid_2

Purchases and sales of subsidiaries, joint ventures, associates and other interests in businesses - Additional information (Detail) - USD ($) $ in Millions	Jul. 16, 2019	Dec. 21, 2018	Dec. 14, 2018	Aug. 01, 2018	Jun. 01, 2018	Sep. 01, 2017	Feb. 26, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure Of Acquisitions And Disposals [Line Items]
Current trade receivables								$ 2,543	$ 2,097
Profit before taxation								15,391	11,119	$ 18,167
Disposals of subsidiaries, joint ventures, unincorporated joint operations and associates								10	(80)	7,733
Expected unconditional royalty payments to be received								113	124
Discontinued operations
Disclosure Of Acquisitions And Disposals [Line Items]
Disposal amount				$ 1,700
Discontinued operations | Yancoal Australia Limited
Disclosure Of Acquisitions And Disposals [Line Items]
Disposal amount						$ 2,690
Cash consideration for disposal						$ 2,450					$ 2,540
Ownership interest in joint venture disposed						(100.00%)
Expected unconditional royalty payments to be received						$ 240		$ 10
Unconditional guaranteed royalty payments received											$ 110
Unconditional guaranteed royalty received									20	90
Discontinued operations | Yancoal Australia Limited | Cash proceeds from previous business combination
Disclosure Of Acquisitions And Disposals [Line Items]
Expected unconditional royalty payments to be received							$ 10
Rossing Uranium Limited
Disclosure Of Acquisitions And Disposals [Line Items]
Profit before taxation	$ 289
Rossing Uranium Limited | Discontinued operations
Disclosure Of Acquisitions And Disposals [Line Items]
Proportion of ownership interest disposed	68.62%
Disposal amount	$ 6.5
Cash consideration for disposal	118
Losses on disposals of investments	289
Cumulative currency translation losses from recycled currency translation reserves	$ 212
Whitehaven Coal Limited | Discontinued operations
Disclosure Of Acquisitions And Disposals [Line Items]
Disposal amount					$ 200
Ownership interest in joint venture disposed					(75.00%)
Cash received from disposals					$ 150
Gains on disposals of projects					195
Whitehaven Coal Limited | Due within 1 year | Discontinued operations
Disclosure Of Acquisitions And Disposals [Line Items]
Current trade receivables					$ 50
Dunkerque Aluminium Smelter
Disclosure Of Acquisitions And Disposals [Line Items]
Disposal amount			$ 500
Profit before taxation			$ 128
Proceeds from sale of a business										385
Grasberg
Disclosure Of Acquisitions And Disposals [Line Items]
Disposal amount		$ 3,500
Gains on disposals of projects		2,146
Disposals of subsidiaries, joint ventures, unincorporated joint operations and associates		3,392
Grasberg | Copper and Gold Revenues
Disclosure Of Acquisitions And Disposals [Line Items]
Revenues, net of capital contribution.		$ 107
Elysis
Disclosure Of Acquisitions And Disposals [Line Items]
Cash investment in joint venture										5
Fare value of patents										171
Fair value of intellectual property										$ 141
Hail Creek
Disclosure Of Acquisitions And Disposals [Line Items]
Ownership interest in joint venture disposed				(82.00%)
Hail Creek | Discontinued operations
Disclosure Of Acquisitions And Disposals [Line Items]
Ownership interest in joint venture disposed				82.00%
Net proceeds disposal of project				$ 1,545					$ 26
Profit before taxation				$ 1,141
Valeria Project | Discontinued operations
Disclosure Of Acquisitions And Disposals [Line Items]
Ownership interest in joint venture disposed				(71.20%)
Net proceeds disposal of project				$ 170
Valeria Project | Discontinued operations | Land and Investments
Disclosure Of Acquisitions And Disposals [Line Items]
Net proceeds disposal of project				87
Profit before taxation				18
Valeria Project | Discontinued operations | Undeveloped Properties
Disclosure Of Acquisitions And Disposals [Line Items]
Cash received from disposals				83
Profit before taxation				83
Kestrel Underground Coal Mine | Discontinued operations
Disclosure Of Acquisitions And Disposals [Line Items]
Disposal amount				$ 2,250
Ownership interest in joint venture disposed				(80.00%)
Net proceeds disposal of project				$ 2,270
Profit before taxation				$ 1,010

Directors' and key management_3

Directors' and key management remuneration - Summary of aggregate remuneration calculated in accordance with UK companies act 2006 (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Directors And Key Management Remuneration [Abstract]
Emoluments	$ 6,686	$ 7,524	$ 9,069
Long-term incentive plans	8,974	4,748	2,923
Total	15,660	12,272	11,992
Pension contributions: defined contribution plans	29	42	80
Gains made on exercise of share options	$ 0	$ 0	$ 107

Directors' and key management_4

Directors' and key management remuneration - Additional information (Detail)	12 Months Ended
	Dec. 31, 2020USD ($)Director	Dec. 31, 2019USD ($)Director	Dec. 31, 2018USD ($)Director
Disclosure Of Directors And Key Management Remuneration [Line Items]
Aggregate remuneration incurred	$ 59,797,000	$ 40,494,000	$ 39,592,000
Aggregate pension contribution to defined contribution plans	369,000	477,000	629,000
Other employment costs	$ 2,130,000	$ 2,066,000	$ 2,360,000
Defined Benefit Plan
Disclosure Of Directors And Key Management Remuneration [Line Items]
Number of directors accrued retirement benefits under defined contribution arrangements | Director	0	0	0
Defined Contribution Plans
Disclosure Of Directors And Key Management Remuneration [Line Items]
Number of directors accrued retirement benefits under defined contribution arrangements | Director	2	2	3
Rio Tinto plc
Disclosure Of Directors And Key Management Remuneration [Line Items]
Aggregate remuneration incurred	$ 14,983,000	$ 11,565,000	$ 11,465,000
Aggregate pension contribution to defined contribution plans	29,000	42,000	80,000
Rio Tinto Limited
Disclosure Of Directors And Key Management Remuneration [Line Items]
Aggregate pension contribution to defined contribution plans	0	0	0
Aggregate remuneration including pension contributions and other retirement benefits	$ 707,000	$ 749,000	$ 607,000

Directors' and key management_5

Directors' and key management remuneration - Summary of aggregate compensation representing the expense recognised under IFRS (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Directors And Key Management Remuneration [Abstract]
Short-term employee benefits and costs	$ 21,685	$ 22,075	$ 23,978
Post-employment benefits	369	477	629
Employment termination benefits	2,789	310	69
Share-based payments	34,954	17,632	14,916
Total	$ 59,797	$ 40,494	$ 39,592

Auditors' remuneration - Audito

Auditors' remuneration - Auditors' remuneration (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Auditors Remuneration [Line Items]
Total audit	$ 17.3	$ 16.4	$ 16.7
Audit-related assurance service	0.8	0.8	0.9
Other assurance services	1.4	1.9	3.3
Total assurance services	2.2	2.7	4.2
Tax compliance	0	0.1	0
Other non-audit services not covered above	0.1	0	0.2
Total non-audit services	2.3	2.8	4.4
Total Group Auditors’ remuneration	19.6	19.2	21.1
Audit of the financial statements of the Group’s subsidiaries(c)	0.6	1.4	1.4
Fees in respect of pension scheme audits	0.1	0.1	0.1
Total audit fees payable to other accounting firms	0.7	1.5	1.5
Rio Tinto
Auditors Remuneration [Line Items]
Total audit	11	9.6	9.2
Subsidiaries
Auditors Remuneration [Line Items]
Total audit	$ 6.3	$ 6.8	$ 7.5

Related-party transactions - Su

Related-party transactions - Summary of transactions and balances with equity accounted units (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of transactions between related parties [Line Items]
Dividends from equity accounted units	$ 594	$ 669	$ 800
Investments in equity accounted units	3,764	3,971
Loans to equity accounted units	41	39
Investment in equity accounted units
Disclosure of transactions between related parties [Line Items]
Purchases from equity accounted units	(960)	(1,155)	(1,209)
Sales to equity accounted units	271	268	493
Dividends from equity accounted units	594	669	800
Net funding of equity accounted units	(43)	(33)	(9)
Investments in equity accounted units	3,764	3,971	4,299
Loans to equity accounted units	41	39	38
Trade and other receivables: amounts due from equity accounted units	251	259	278
Trade and other payables: amounts due to equity accounted units	$ (241)	$ (271)	$ (223)

Exchange rates in US$ - Summary

Exchange rates in US$ - Summary of principal exchange rate used in preparation of financial statements (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Sterling
Disclosure Of Foreign Exchange Rates [Line Items]
Full-year average exchange rate per U.S.$ (in dollars per share)	1.28	1.28	1.34
Year-end exchange rate per U.S.$ (in dollars per share)	1.36	1.31	1.27
Australian dollar
Disclosure Of Foreign Exchange Rates [Line Items]
Full-year average exchange rate per U.S.$ (in dollars per share)	0.69	0.70	0.75
Year-end exchange rate per U.S.$ (in dollars per share)	0.77	0.70	0.70
Canadian dollar
Disclosure Of Foreign Exchange Rates [Line Items]
Full-year average exchange rate per U.S.$ (in dollars per share)	0.75	0.75	0.77
Year-end exchange rate per U.S.$ (in dollars per share)	0.78	0.77	0.73
Euro
Disclosure Of Foreign Exchange Rates [Line Items]
Full-year average exchange rate per U.S.$ (in dollars per share)	1.14	1.12	1.18
Year-end exchange rate per U.S.$ (in dollars per share)	1.23	1.12	1.14
South African rand
Disclosure Of Foreign Exchange Rates [Line Items]
Full-year average exchange rate per U.S.$ (in dollars per share)	0.061	0.069	0.076
Year-end exchange rate per U.S.$ (in dollars per share)	0.068	0.071	0.069

Share-based payments - Charge h

Share-based payments - Charge has been recognised in income statement for Rio Tinto's share-based incentive plans, and the related liability (for cash-settled plans) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of terms and conditions of share-based payment arrangement [line items]
Charge recognised for the year	$ 138	$ 123	$ 122
Liability at the end of the year	7	19
Equity-settled awards
Disclosure of terms and conditions of share-based payment arrangement [line items]
Charge recognised for the year	131	118	118
Liability at the end of the year	0	0
Cash-settled awards
Disclosure of terms and conditions of share-based payment arrangement [line items]
Charge recognised for the year	7	5	$ 4
Liability at the end of the year	$ 7	$ 19

Share-based payments - Addition

Share-based payments - Additional information (Detail)	12 Months Ended
	Dec. 31, 2020Instrument£ / shares	Dec. 31, 2019USD ($)shares	Dec. 31, 2020USD ($)shares
Disclosure of terms and conditions of share-based payment arrangement [line items]
Percentage of cancellations employees electing to withdraw their investment shares before vesting of their matching shares	15.00%
Liability for cash-settled awards | $		$ 19,000,000	$ 7,000,000
Rio Tinto plc
Disclosure of terms and conditions of share-based payment arrangement [line items]
Percentage of share-based payment charge for plan	100.00%	100.00%
Rio Tinto Limited
Disclosure of terms and conditions of share-based payment arrangement [line items]
Percentage of share-based payment charge for plan	100.00%	100.00%
Performance share plans
Disclosure of terms and conditions of share-based payment arrangement [line items]
Percentage of forfeitures, prior to vesting, on outstanding awards	5.00%	5.00%
Description of vesting requirements for share-based payment arrangement	Forfeitures prior to vesting are assumed at 5% per annum of outstanding awards (2017: 5% per annum).
Number of global mining comparators | Instrument	10
Performance share plans | Rio Tinto plc
Disclosure of terms and conditions of share-based payment arrangement [line items]
Cash-settled awards outstanding | shares			48,191
Liability for cash-settled awards | $			$ 3,000,000
Performance share plans | Rio Tinto plc | Top of range
Disclosure of terms and conditions of share-based payment arrangement [line items]
Cash-settled awards outstanding | shares		49,019
Liability for cash-settled awards | $		$ 13,000,000
Performance share plans | Rio Tinto Limited
Disclosure of terms and conditions of share-based payment arrangement [line items]
Cash-settled awards outstanding | shares		276,722	15,164
Management share plans
Disclosure of terms and conditions of share-based payment arrangement [line items]
Percentage of forfeitures, prior to vesting, on outstanding awards	7.00%	7.00%
Description of vesting requirements for share-based payment arrangement	The vesting of these awards is dependent on service conditions being met.
Bonus deferral plans
Disclosure of terms and conditions of share-based payment arrangement [line items]
Description of method of settlement for share-based payment arrangement	3	3
Description of vesting requirements for share-based payment arrangement	The vesting of these awards is dependent only on service conditions being met.
Global employee share plans
Disclosure of terms and conditions of share-based payment arrangement [line items]
Percentage of forfeitures, prior to vesting, on outstanding awards	5.00%	5.00%
Description of vesting requirements for share-based payment arrangement	The vesting of these matching awards is dependent on service conditions being met and the continued holding of investment shares by the participant until vesting.
Share Incentive Plans
Disclosure of terms and conditions of share-based payment arrangement [line items]
Liability for cash-settled awards | $			$ 4,000,000
Share Incentive Plans | Top of range
Disclosure of terms and conditions of share-based payment arrangement [line items]
Liability for cash-settled awards | $		$ 6,000,000
Share Incentive Plans | Rio Tinto plc
Disclosure of terms and conditions of share-based payment arrangement [line items]
Cash-settled awards outstanding | shares		52,881	89,253
Share Incentive Plans | Rio Tinto Limited
Disclosure of terms and conditions of share-based payment arrangement [line items]
Cash-settled awards outstanding | shares		81,050	14,878
Executive Directors And Product Group Executives | Bonus deferral plans
Disclosure of terms and conditions of share-based payment arrangement [line items]
Description of method of settlement for share-based payment arrangement	50
Description of vesting requirements for share-based payment arrangement	50% of the bonuses
Other Executives | Bonus deferral plans
Disclosure of terms and conditions of share-based payment arrangement [line items]
Description of method of settlement for share-based payment arrangement	25
Ranges Of Exercise Prices For Outstanding Share Options Three | Share Option Plan | Rio Tinto plc | Bottom of range
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price of outstanding share options | £ / shares	£ 16
Ranges Of Exercise Prices For Outstanding Share Options Three | Share Option Plan | Rio Tinto plc | Top of range
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price of outstanding share options | £ / shares	25
Ranges Of Exercise Prices For Outstanding Share Options Four | Share Option Plan | Rio Tinto Limited
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price of outstanding share options | £ / shares	£ 33

Share-based payments - Summary

Share-based payments - Summary of performance share plans (Detail) - Performance share plans	12 Months Ended
	Dec. 31, 2020shares£ / shares	Dec. 31, 2020shares$ / shares	Dec. 31, 2019shares£ / shares	Dec. 31, 2019shares$ / shares
Rio Tinto plc
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of non-vested shares at beginning balance	3,803,394	3,803,394	3,845,082	3,845,082
Number of non-vested shares, awarded	716,111	716,111	755,735	755,735
Number of non-vested shares, forfeited	(136,030)	(136,030)	(122,961)	(122,961)
Number of non-vested shares, failed performance conditions	(145,661)	(145,661)	(384,130)	(384,130)
Number of non-vested shares, vested	(459,773)	(459,773)	(290,332)	(290,332)
Number of non-vested shares at ending balance	3,778,041	3,778,041	3,803,394	3,803,394
Weighted average fair value at grant date, non-vested shares at beginning balance | £ / shares	£ 22.20		£ 21.86
Weighted average fair value at grant date, non-vested shares, awarded | £ / shares	13.55		24.68
Weighted average fair value at grant date, non-vested shares, forfeited | £ / shares	21.13		23.95
Weighted average fair value at grant date, non-vested shares, failed performance conditions | £ / shares	16.64		23.79
Weighted average fair value at grant date, non-vested shares, vested | £ / shares	20.55		21.36
Weighted average fair value at grant date, non-vested shares ending balance | £ / shares	£ 21.01		£ 22.20
Number of vested awards settled in shares during the year (including dividend shares applied on vesting)	476,602	476,602	339,821	339,821
Number of vested awards settled in cash during the year (including dividend shares applied on vesting)	108,887	108,887	1,279	1,279
Weighted average share price, Vested awards settled in shares during the year (including dividend shares applied on vesting) | £ / shares	£ 43.13		£ 45.52
Weighted average share price, Vested awards settled in cash during the year (including dividend shares applied on vesting) | £ / shares	£ 43.13		£ 43.65
Rio Tinto Limited
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of non-vested shares at beginning balance	1,636,517	1,636,517	1,797,279	1,797,279
Number of non-vested shares, awarded	198,863	198,863	297,189	297,189
Number of non-vested shares, forfeited	(178,921)	(178,921)	(126,775)	(126,775)
Number of non-vested shares, failed performance conditions	(63,852)	(63,852)	(188,956)	(188,956)
Number of non-vested shares, vested	(201,234)	(201,234)	(142,220)	(142,220)
Number of non-vested shares at ending balance	1,391,373	1,391,373	1,636,517	1,636,517
Weighted average fair value at grant date, non-vested shares at beginning balance | $ / shares		$ 45.11		$ 43.34
Weighted average fair value at grant date, non-vested shares, awarded | $ / shares		33.56		54.55
Weighted average fair value at grant date, non-vested shares, forfeited | $ / shares		46.37		44.02
Weighted average fair value at grant date, non-vested shares, failed performance conditions | $ / shares		33.38		46.42
Weighted average fair value at grant date, non-vested shares, vested | $ / shares		41.21		41.72
Weighted average fair value at grant date, non-vested shares ending balance | $ / shares		$ 44.40		$ 45.11
Number of vested awards settled in shares during the year (including dividend shares applied on vesting)	217,287	217,287	151,607	151,607
Number of vested awards settled in cash during the year (including dividend shares applied on vesting)	28,208	28,208	1,347	1,347
Weighted average share price, Vested awards settled in shares during the year (including dividend shares applied on vesting) | $ / shares		$ 93.48		$ 100.30
Weighted average share price, Vested awards settled in cash during the year (including dividend shares applied on vesting) | $ / shares		$ 93.82		$ 92.97

Share-based payments - Manageme

Share-based payments - Management Share Plans, Bonus Deferral Plans, Global Employee Share Plans and UK Share Plan (combined) (Detail)	12 Months Ended
	Dec. 31, 2020t£ / shares	Dec. 31, 2020t$ / shares	Dec. 31, 2019t£ / shares	Dec. 31, 2019t$ / shares
Management share plans, bonus deferral plans, global employee share plans and uk share plan (combined) | Rio Tinto plc
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of non-vested shares at beginning balance	2,613,013	2,613,013	3,042,020	3,042,020
Number of non-vested shares, awarded	1,190,528	1,190,528	1,043,817	1,043,817
Number of non-vested shares, forfeited	(99,038)	(99,038)	(224,402)	(224,402)
Number of non-vested shares, Cancelled	(33,955)	(33,955)	(24,043)	(24,043)
Number of non-vested shares, vested	(1,019,687)	(1,019,687)	(1,224,379)	(1,224,379)
Number of non-vested shares at ending balance	2,650,861	2,650,861	2,613,013	2,613,013
Weighted average fair value at grant date, non-vested shares at beginning balance	£ 37.14		£ 31.43
Weighted average fair value at grant date, non-vested shares, awarded	36.27		40.41
Weighted average fair value at grant date, non-vested shares, forfeited	44.42		39.46
Weighted average fair value at grant date, non-vested shares, cancelled	37.72		32.87
Weighted average fair value at grant date, non-vested shares, vested	34.46		25.40
Weighted average fair value at grant date, non-vested shares ending balance	£ 37.50		£ 37.14
Management share plans, bonus deferral plans, global employee share plans and uk share plan (combined) | Rio Tinto Limited
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of non-vested shares at beginning balance	2,273,669	2,273,669	2,613,930	2,613,930
Number of non-vested shares, awarded	921,070	921,070	846,008	846,008
Number of non-vested shares, forfeited	(60,935)	(60,935)	(174,025)	(174,025)
Number of non-vested shares, Cancelled	(50,354)	(50,354)	(35,481)	(35,481)
Number of non-vested shares, vested	(866,716)	(866,716)	(976,763)	(976,763)
Number of non-vested shares at ending balance	2,216,734	2,216,734	2,273,669	2,273,669
Weighted average fair value at grant date, non-vested shares at beginning balance | $ / shares		$ 75.46		$ 61.71
Weighted average fair value at grant date, non-vested shares, awarded | $ / shares		83.20		86.56
Weighted average fair value at grant date, non-vested shares, forfeited | $ / shares		85.01		72.18
Weighted average fair value at grant date, non-vested shares, cancelled | $ / shares		71.45		60.91
Weighted average fair value at grant date, non-vested shares, vested | $ / shares		65.19		49.39
Weighted average fair value at grant date, non-vested shares ending balance | $ / shares		$ 82.52		$ 75.46
Management share plans | Rio Tinto plc
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of non-vested shares at beginning balance	1,398,039	1,398,039
Number of non-vested shares at ending balance	1,352,759	1,352,759	1,398,039	1,398,039
Weighted average fair value at grant date, non-vested shares at beginning balance	£ 38.68
Weighted average fair value at grant date, non-vested shares ending balance	£ 38.73		£ 38.68
Number of vested awards settled in shares during the year (including dividend shares applied on vesting)	707,133	707,133	681,242	681,242
Weighted average share price, Vested awards settled in shares during the year (including dividend shares applied on vesting)	£ 42.26		£ 43.68
Management share plans | Rio Tinto Limited
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of non-vested shares at beginning balance	1,363,601	1,363,601
Number of non-vested shares at ending balance	1,291,203	1,291,203	1,363,601	1,363,601
Weighted average fair value at grant date, non-vested shares at beginning balance | $ / shares		$ 78.67
Weighted average fair value at grant date, non-vested shares ending balance | $ / shares		$ 85.80		$ 78.67
Number of vested awards settled in shares during the year (including dividend shares applied on vesting)	640,948	640,948	582,948	582,948
Weighted average share price, Vested awards settled in shares during the year (including dividend shares applied on vesting) | $ / shares		$ 97.74		$ 93.05
Bonus deferral plans | Rio Tinto plc
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of non-vested shares at beginning balance	192,878	192,878
Number of non-vested shares at ending balance	211,905	211,905	192,878	192,878
Weighted average fair value at grant date, non-vested shares at beginning balance	£ 41.95
Weighted average fair value at grant date, non-vested shares ending balance	£ 36.14		£ 41.95
Number of vested awards settled in shares during the year (including dividend shares applied on vesting)	111,233	111,233	163,076	163,076
Weighted average share price, Vested awards settled in shares during the year (including dividend shares applied on vesting)	£ 49.71		£ 42.53
Number of vested awards settled in cash during the year (including dividend shares applied on vesting) | t	19,617	19,617	0	0
Weighted average share price, Vested awards settled in cash during the year (including dividend shares applied on vesting)	£ 48.34		£ 0
Bonus deferral plans | Rio Tinto Limited
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of non-vested shares at beginning balance	87,930	87,930
Number of non-vested shares at ending balance	53,324	53,324	87,930	87,930
Weighted average fair value at grant date, non-vested shares at beginning balance | $ / shares		$ 87.81
Weighted average fair value at grant date, non-vested shares ending balance | $ / shares		$ 85.53		$ 87.81
Number of vested awards settled in shares during the year (including dividend shares applied on vesting)	63,404	63,404	85,142	85,142
Weighted average share price, Vested awards settled in shares during the year (including dividend shares applied on vesting) | $ / shares		$ 101.96		$ 97.30
Number of vested awards settled in cash during the year (including dividend shares applied on vesting) | t	0	0	0	0
Weighted average share price, Vested awards settled in cash during the year (including dividend shares applied on vesting)	£ 0		£ 0
Global employee share plans | Rio Tinto plc
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of non-vested shares at beginning balance	982,932	982,932
Number of non-vested shares at ending balance	1,050,608	1,050,608	982,932	982,932
Weighted average fair value at grant date, non-vested shares at beginning balance	£ 33.98
Weighted average fair value at grant date, non-vested shares ending balance	£ 36.06		£ 33.98
Number of vested awards settled in shares during the year (including dividend shares applied on vesting)	401,169	401,169	543,426	543,426
Weighted average share price, Vested awards settled in shares during the year (including dividend shares applied on vesting)	£ 43.82		£ 43.04
Global employee share plans | Rio Tinto Limited
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of non-vested shares at beginning balance	822,138	822,138
Number of non-vested shares at ending balance	872,207	872,207	822,138	822,138
Weighted average fair value at grant date, non-vested shares at beginning balance | $ / shares		$ 68.82
Weighted average fair value at grant date, non-vested shares ending balance | $ / shares		$ 77.47		$ 68.82
Number of vested awards settled in shares during the year (including dividend shares applied on vesting)	299,381	299,381	421,614	421,614
Weighted average share price, Vested awards settled in shares during the year (including dividend shares applied on vesting) | $ / shares		$ 98.60		$ 91.50
UK share plan | Rio Tinto plc
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of non-vested shares at beginning balance	39,164	39,164
Number of non-vested shares at ending balance	35,589	35,589	39,164	39,164
Weighted average fair value at grant date, non-vested shares at beginning balance	£ 37.86
Weighted average fair value at grant date, non-vested shares ending balance	£ 41.54		£ 37.86
Number of vested awards settled in shares during the year (including dividend shares applied on vesting)	2,392	2,392	34,196	34,196
Weighted average share price, Vested awards settled in shares during the year (including dividend shares applied on vesting)	£ 45.73		£ 42.21
UK share plan | Rio Tinto Limited
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of non-vested shares at beginning balance	0	0
Number of non-vested shares at ending balance	0	0	0	0
Weighted average fair value at grant date, non-vested shares at beginning balance	£ 0
Weighted average fair value at grant date, non-vested shares ending balance	£ 0		£ 0
Number of vested awards settled in shares during the year (including dividend shares applied on vesting)	0	0	0	0
Weighted average share price, Vested awards settled in shares during the year (including dividend shares applied on vesting)	£ 0		£ 0

Post-retirement benefits - Summ

Post-retirement benefits - Summary of fair value of plan assets (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of information about defined benefit plans [abstract]
Equities	21.10%	20.40%
– Quoted	17.90%	17.00%
– Private	3.20%	3.40%
Bonds	55.80%	63.40%
– Government fixed income	17.70%	18.40%
– Government inflation-linked	9.60%	16.20%
– Corporate and other publicly quoted	22.60%	24.10%
– Private	5.90%	4.70%
Property	7.50%	8.80%
– Quoted property funds	3.10%	3.40%
– Unquoted property funds	4.40%	5.40%
Qualifying insurance policies	11.30%	3.10%
Cash & other	4.30%	4.30%
Total	100.00%	100.00%

Post-retirement benefits - Addi

Post-retirement benefits - Additional information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of defined benefit plans [Line Items]
Securities included in fair value of plan assets	$ 4,000,000	$ 3,000,000
Defined benefit expenses excluded form unerlying earnings	0	0	$ 0
Past service cost	(2,000,000)	$ 0	(36,000,000)
Excess of service cost over cash paid to defined contribution plans	3,000,000
Estimated contributions to defined benefit pension plans for 2019	$ 150,000,000
Defined benefit obligation weighted average expected future life time	27 years	27 years
Defined benefit obligation weighted average expected future life time at man aged 60 in 2036	28 years	28 years
Healthcare plans
Disclosure of defined benefit plans [Line Items]
Discount rate	2.50%	3.30%
Medical trend rate	6.30%	6.10%
Reduction in medical trend rate	4.60%	4.60%
UK
Disclosure of defined benefit plans [Line Items]
Estimate of the cost of equalising benefits due to court judgement			$ 9,000,000
Past service cost	$ 1,000,000
Discount rate	1.20%	2.00%

Post-retirement benefits - Su_2

Post-retirement benefits - Summary of maturity of defined benefit obligations (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of defined benefit plans [Line Items]
Proportion relating to current employees	21.00%	20.00%	19.00%
Proportion relating to former employees not yet retired	11.00%	12.00%	11.00%
Proportion relating to retirees	68.00%	68.00%	70.00%
Total	100.00%	100.00%	100.00%
Average duration of obligations (years)	14 years 3 months 18 days	14 years 4 months 24 days	13 years 4 months 24 days
Pension benefits
Disclosure of defined benefit plans [Line Items]
Proportion relating to current employees	21.00%
Proportion relating to former employees not yet retired	12.00%
Proportion relating to retirees	67.00%
Total	100.00%
Average duration of obligations (years)	14 years 4 months 24 days
Other Benefits
Disclosure of defined benefit plans [Line Items]
Proportion relating to current employees	19.00%
Proportion relating to former employees not yet retired	0.00%
Proportion relating to retirees	81.00%
Total	100.00%
Average duration of obligations (years)	13 years 6 months

Post-retirement benefits - Su_3

Post-retirement benefits - Summary of geographical distribution of defined benefit obligations (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	100.00%	100.00%	100.00%
Canada
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	53.00%	53.00%	48.00%
UK
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	28.00%	28.00%	28.00%
United States of America
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	10.00%	10.00%	14.00%
Switzerland
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	5.00%	5.00%	5.00%
Other countries
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	4.00%	4.00%	5.00%
Pension benefits
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	100.00%
Pension benefits | Canada
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	54.00%
Pension benefits | UK
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	30.00%
Pension benefits | United States of America
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	7.00%
Pension benefits | Switzerland
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	5.00%
Pension benefits | Other countries
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	4.00%
Other Benefits
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	100.00%
Other Benefits | Canada
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	46.00%
Other Benefits | UK
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	2.00%
Other Benefits | United States of America
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	50.00%
Other Benefits | Switzerland
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	0.00%
Other Benefits | Other countries
Disclosure of defined benefit plans [Line Items]
Defined benefit obligation	2.00%

Post-retirement benefits - Su_4

Post-retirement benefits - Summary of total expense recognised in the income statement (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of net defined benefit liability (asset) [Line Items]
Current employer service cost for defined benefit plans	$ (137)	$ (125)	$ (165)
Past service cost	(2)	0	(36)
Curtailment gains	0	0	2
Settlement (losses)/gains	(1)	51	5
Net interest on net defined benefit liability	(49)	(58)	(79)
Non-investment expenses paid from the plans	(16)	(14)	(15)
Total defined benefit expense	(205)	(146)	(288)
Current employer service cost for defined contribution and industry-wide plans	(264)	(238)	(244)
Total expense recognised in the income statement	(469)	$ (384)	$ (532)
Pension benefits
Disclosure of net defined benefit liability (asset) [Line Items]
Current employer service cost for defined benefit plans	(131)
Past service cost	(2)
Curtailment gains	0
Settlement (losses)/gains	(1)
Net interest on net defined benefit liability	(22)
Non-investment expenses paid from the plans	(16)
Total defined benefit expense	(172)
Current employer service cost for defined contribution and industry-wide plans	(262)
Total expense recognised in the income statement	(434)
Other Benefits
Disclosure of net defined benefit liability (asset) [Line Items]
Current employer service cost for defined benefit plans	(6)
Past service cost	0
Curtailment gains	0
Settlement (losses)/gains	0
Net interest on net defined benefit liability	(27)
Non-investment expenses paid from the plans	0
Total defined benefit expense	(33)
Current employer service cost for defined contribution and industry-wide plans	(2)
Total expense recognised in the income statement	$ (35)

Post-retirement benefits - Su_5

Post-retirement benefits - Summary of total amount recognised in other comprehensive income before tax (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of net defined benefit liability (asset) [Abstract]
Actuarial (losses)/gains	$ (1,242)	$ (1,295)	$ 1,382
Return on assets, net of interest on assets	768	1,033	(527)
Gain on application of asset ceiling	0	0	52
Total (loss)/gain recognised in other comprehensive income	$ (474)	$ (262)	$ 907

Post-retirement benefits - Su_6

Post-retirement benefits - Summary of amount recognised in balance sheet (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	$ (2,273)	$ (1,730)	$ (1,551)
Deficits	(3,055)	(2,714)
Surpluses	782	984
Net deficits on pension plans	(1,305)	(831)
Unfunded
Disclosure of information about amounts recognized in balance sheet [Line Items]
Unfunded post-retirement healthcare obligation	(968)	(899)
Pension benefits
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	(1,305)	(831)
Deficits	(2,087)
Surpluses	782
Net deficits on pension plans	(1,305)
Pension benefits | Unfunded
Disclosure of information about amounts recognized in balance sheet [Line Items]
Unfunded post-retirement healthcare obligation	0
Other Benefits
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	(968)	(899)
Deficits	(968)
Surpluses	0
Net deficits on pension plans	0
Other Benefits | Unfunded
Disclosure of information about amounts recognized in balance sheet [Line Items]
Unfunded post-retirement healthcare obligation	(968)
Plan assets
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	14,905	13,923	13,203
Plan assets | Pension benefits
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	14,905	13,923
Plan assets | Other Benefits
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	0	0
Present value of defined benefit obligation
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	(17,178)	(15,653)	$ (14,754)
Present value of defined benefit obligation | Funded
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	(15,731)	(14,311)
Present value of defined benefit obligation | Unfunded
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	(1,447)	(1,342)
Present value of defined benefit obligation | Pension benefits
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	(16,210)	(14,754)
Present value of defined benefit obligation | Pension benefits | Funded
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	(15,731)
Present value of defined benefit obligation | Pension benefits | Unfunded
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	(479)
Present value of defined benefit obligation | Other Benefits
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	(968)	$ (899)
Present value of defined benefit obligation | Other Benefits | Funded
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	0
Present value of defined benefit obligation | Other Benefits | Unfunded
Disclosure of information about amounts recognized in balance sheet [Line Items]
Net deficit to be shown in the balance sheet	$ (968)

Post-retirement benefits - Su_7

Post-retirement benefits - Summary of funding policy and contributions to plans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of net defined benefit liability (asset) [Line Items]
Contributions to defined benefit plans	$ 201	$ 257	$ 248
Contributions to defined contribution plans	261	235	244
Total	462	$ 492	$ 492
Pension benefits
Disclosure of net defined benefit liability (asset) [Line Items]
Contributions to defined benefit plans	169
Contributions to defined contribution plans	259
Total	428
Other Benefits
Disclosure of net defined benefit liability (asset) [Line Items]
Contributions to defined benefit plans	32
Contributions to defined contribution plans	2
Total	$ 34

Post-retirement benefits - Su_8

Post-retirement benefits - Summary of movement in net defined benefit liability (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of net defined benefit liability (asset) [Line Items]
Beginning balance	$ (1,730)	$ (1,551)
Amounts recognised in income statement	(205)	(146)	$ (288)
Amounts recognised in other comprehensive income	(474)	(262)	907
Employer contributions	201	257	248
Arrangements added/divested	0	(5)
Assets transferred to defined contribution section	(3)	(3)
Currency exchange rate (loss)	(62)	(20)
Ending balance	(2,273)	(1,730)	$ (1,551)
Pension benefits
Disclosure of net defined benefit liability (asset) [Line Items]
Beginning balance	(831)
Amounts recognised in income statement	(172)
Amounts recognised in other comprehensive income	(416)
Employer contributions	169
Arrangements added/divested	0
Assets transferred to defined contribution section	(3)
Currency exchange rate (loss)	(52)
Ending balance	(1,305)	(831)
Other Benefits
Disclosure of net defined benefit liability (asset) [Line Items]
Beginning balance	(899)
Amounts recognised in income statement	(33)
Amounts recognised in other comprehensive income	(58)
Employer contributions	32
Arrangements added/divested	0
Assets transferred to defined contribution section	0
Currency exchange rate (loss)	(10)
Ending balance	$ (968)	$ (899)

Post-retirement benefits - Su_9

Post-retirement benefits - Summary of movement in present value of obligation (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Changes in net defined benefit liability (asset) [abstract]
Beginning balance	$ (1,730)	$ (1,551)
Current employer service costs	137	125	$ 165
Past service cost	2	0	36
Settlements	1	(51)	(5)
Interest on obligation	(49)	(58)	(79)
Changes in financial assumptions (loss)	1,242	1,295	(1,382)
Arrangements added/divested	0	(5)
Currency exchange rate (loss)	(62)	(20)
Ending balance	(2,273)	(1,730)	(1,551)
Pension benefits
Changes in net defined benefit liability (asset) [abstract]
Beginning balance	(831)
Current employer service costs	131
Past service cost	2
Settlements	1
Interest on obligation	(22)
Arrangements added/divested	0
Currency exchange rate (loss)	(52)
Ending balance	(1,305)	(831)
Other Benefits
Changes in net defined benefit liability (asset) [abstract]
Beginning balance	(899)
Arrangements added/divested	0
Currency exchange rate (loss)	(10)
Ending balance	(968)	(899)
Present value of defined benefit obligation
Changes in net defined benefit liability (asset) [abstract]
Beginning balance	(15,653)	(14,754)
Current employer service costs	(137)	(125)
Past service cost	(2)	0
Settlements	6	638
Interest on obligation	(384)	(476)
Contributions by plan participants	(22)	(23)
Benefits paid	778	862
Experience gains	61	111
Changes in financial assumptions (loss)	(1,442)	(1,447)
Changes in demographic assumptions gain	139	41
Arrangements added/divested	0	(5)
Currency exchange rate (loss)	(522)	(475)
Ending balance	(17,178)	(15,653)	$ (14,754)
Present value of defined benefit obligation | Pension benefits
Changes in net defined benefit liability (asset) [abstract]
Beginning balance	(14,754)
Current employer service costs	(131)
Past service cost	(2)
Settlements	6
Interest on obligation	(357)
Contributions by plan participants	(22)
Benefits paid	746
Experience gains	46
Changes in financial assumptions (loss)	(1,357)
Changes in demographic assumptions gain	127
Arrangements added/divested	0
Currency exchange rate (loss)	(512)
Ending balance	(16,210)	(14,754)
Present value of defined benefit obligation | Other Benefits
Changes in net defined benefit liability (asset) [abstract]
Beginning balance	(899)
Current employer service costs	(6)
Past service cost	0
Settlements	0
Interest on obligation	(27)
Contributions by plan participants	0
Benefits paid	32
Experience gains	15
Changes in financial assumptions (loss)	(85)
Changes in demographic assumptions gain	12
Arrangements added/divested	0
Currency exchange rate (loss)	(10)
Ending balance	$ (968)	$ (899)

Post-retirement benefits - S_10

Post-retirement benefits - Summary of movement in plan assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of net defined benefit liability (asset) [Line Items]
Beginning balance	$ (1,730)	$ (1,551)
Settlements	1	(51)	$ (5)
Interest on obligation	(49)	(58)	(79)
Employer contributions	201	257	248
Non-investment expenses	(16)	(14)	(15)
Return on plan assets, net of interest on assets	(768)	(1,033)	527
Assets transferred to defined contribution section	(3)	(3)
Currency exchange rate (loss)	(62)	(20)
Ending balance	(2,273)	(1,730)	(1,551)
Plan assets
Disclosure of net defined benefit liability (asset) [Line Items]
Beginning balance	13,923	13,203
Settlements	(7)	(587)
Interest on obligation	335	418
Contributions by plan participants	22	23
Employer contributions	201	257
Benefits paid	(778)	(862)
Non-investment expenses	(16)	(14)
Return on plan assets, net of interest on assets	768	1,033
Currency exchange rate (loss)	460	455
Ending balance	14,905	13,923	$ 13,203
Pension benefits
Disclosure of net defined benefit liability (asset) [Line Items]
Beginning balance	(831)
Settlements	1
Interest on obligation	(22)
Employer contributions	169
Non-investment expenses	(16)
Currency exchange rate (loss)	(52)
Ending balance	(1,305)	(831)
Pension benefits | Plan assets
Disclosure of net defined benefit liability (asset) [Line Items]
Beginning balance	13,923
Settlements	(7)
Interest on obligation	335
Contributions by plan participants	22
Employer contributions	169
Benefits paid	(746)
Non-investment expenses	(16)
Return on plan assets, net of interest on assets	768
Assets transferred to defined contribution section	(3)
Currency exchange rate (loss)	460
Ending balance	14,905	13,923
Other Benefits
Disclosure of net defined benefit liability (asset) [Line Items]
Beginning balance	(899)
Employer contributions	32
Currency exchange rate (loss)	(10)
Ending balance	(968)	(899)
Other Benefits | Plan assets
Disclosure of net defined benefit liability (asset) [Line Items]
Beginning balance	0
Settlements	0
Interest on obligation	0
Contributions by plan participants	0
Employer contributions	32
Benefits paid	(32)
Non-investment expenses	0
Return on plan assets, net of interest on assets	0
Assets transferred to defined contribution section	0
Currency exchange rate (loss)	0
Ending balance	$ 0	$ 0

Post-retirement benefits - S_11

Post-retirement benefits - Summary of main assumptions rate for valuations of plans (Detail)	Dec. 31, 2020	Dec. 31, 2019
Disclosure of defined benefit plans [Line Items]
Assumption for the consumer price index	2.10%	2.00%
Canada
Disclosure of defined benefit plans [Line Items]
Discount rate	2.50%	3.10%
Inflation	1.60%	1.60%
Rate of increase in pensions	0.10%	0.10%
Rate of increase in salaries	2.80%	2.80%
UK
Disclosure of defined benefit plans [Line Items]
Discount rate	1.20%	2.00%
Inflation	2.90%	2.90%
Rate of increase in pensions	2.50%	2.50%
Rate of increase in salaries	3.60%	3.50%
United States of America
Disclosure of defined benefit plans [Line Items]
Discount rate	2.20%	3.10%
Inflation	2.10%	2.00%
Rate of increase in pensions	0.00%	0.00%
Rate of increase in salaries	3.60%	3.50%
Switzerland
Disclosure of defined benefit plans [Line Items]
Discount rate	0.10%	0.20%
Inflation	0.90%	1.10%
Rate of increase in pensions	0.50%	0.20%
Rate of increase in salaries	1.90%	2.10%

Post-retirement benefits - Resu

Post-retirement benefits - Results summary of sensitivity analysis (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Discount rate | Pension benefits
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Increase of actuarial assumption	$ 988	$ 894
Decrease of actuarial assumption	$ (1,186)	$ (1,057)
Increase of percentage points	0.50%	0.50%
Decrease of percentage points	0.50%	0.50%
Discount rate | Other benefits
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Increase of actuarial assumption	$ 62	$ 56
Decrease of actuarial assumption	$ (66)	$ (60)
Increase of percentage points	0.50%	0.50%
Decrease of percentage points	0.50%	0.50%
Inflation | Pension benefits
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Increase of actuarial assumption	$ (484)	$ (447)
Decrease of actuarial assumption	$ 450	$ 422
Increase of percentage points	0.50%	0.50%
Decrease of percentage points	0.50%	0.50%
Inflation | Other benefits
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Increase of actuarial assumption	$ (19)	$ (17)
Decrease of actuarial assumption	$ 17	$ 15
Increase of percentage points	0.50%	0.50%
Decrease of percentage points	0.50%	0.50%
Salary increases | Pension benefits
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Increase of actuarial assumption	$ (81)	$ (55)
Decrease of actuarial assumption	$ 72	$ 54
Increase of percentage points	0.50%	0.50%
Decrease of percentage points	0.50%	0.50%
Salary increases | Other benefits
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Increase of actuarial assumption	$ (1)	$ (1)
Decrease of actuarial assumption	$ 1	$ 1
Increase of percentage points	0.50%	0.50%
Decrease of percentage points	0.50%	0.50%
Demographic – allowance for future improvements in longevity | Pension benefits
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Increase of actuarial assumption	$ 520	$ 443
Decrease of actuarial assumption	$ (562)	$ (465)
Increase in actuarial assumption of longevity trend	1 year	1 year
Decrease in actuarial assumption of longevity trend	1 year	1 year
Demographic – allowance for future improvements in longevity | Other benefits
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Increase of actuarial assumption	$ 19	$ 18
Decrease of actuarial assumption	$ (19)	$ (18)
Increase in actuarial assumption of longevity trend	1 year	1 year
Decrease in actuarial assumption of longevity trend	1 year	1 year

Events after the balance shee_2

Events after the balance sheet date (Details) $ in Millions, $ in Millions	36 Months Ended
	Dec. 31, 2018AUD ($)	Dec. 31, 2018USD ($)	Mar. 02, 2021AUD ($)	Mar. 02, 2021USD ($)
Disclosure of non-adjusting events after reporting period [line items]
Income taxes paid	$ 8,400	$ 6,400
Tax contingent liability | Tax assessments received
Disclosure of non-adjusting events after reporting period [line items]
Contingent liabilities, amount not recorded, tax			$ 359.4	$ 279.8
Contingent liabilities, amount not recorded, interest			$ 47.1	$ 36.7
Percentage of tax paid upfront			50.00%	50.00%

Rio Tinto financial informati_3

Rio Tinto financial information by business unit - Schedule of financial information by business unit (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)Employee	Dec. 31, 2019USD ($)Employee	Dec. 31, 2018USD ($)Employee
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 44,611	$ 43,165	$ 40,522
Impairment charges	(1,272)	(3,487)	(132)
Depreciation & amortisation in subsidiaries excluding capitalised depreciation	(4,074)	(4,272)	(3,909)
Finance items	(1,751)	(648)	(33)
Profit (loss) before tax	15,391	11,119	18,167
Profit before taxation	17,142	11,767	18,200
Profit/(loss) after tax – attributable to owners of Rio Tinto	9,769	8,010	13,638
Capital expenditure	6,144	5,439	4,844
Depreciation and amortisation expense proportionately consolidated	4,279	4,384	4,015
Operating assets	$ 47,718	$ 44,183	$ 43,431
Number of employees | Employee	47,474	46,007	47,458
Pre-tax gains on disposals of property, plant and equipment	$ 45	$ 49	$ 586
Capital expenditure per cash flow statement	6,189	5,488	5,430
Net cash/(debt)	(664)	(3,651)	255
Equity attributable to owners of Rio Tinto	47,054	40,532	43,686
Net assets of disposal groups held for sale
Disclosure of operating segments [Line Items]
Operating assets	0	0	440
Diamonds
Disclosure of operating segments [Line Items]
Consolidated sales revenue	459	619	695
Uranium
Disclosure of operating segments [Line Items]
Consolidated sales revenue	299	375	415
Other Operations
Disclosure of operating segments [Line Items]
Consolidated sales revenue	18	18	9
Profit before taxation	0	(77)	(70)
Profit/(loss) after tax – attributable to owners of Rio Tinto	(54)	(89)	(102)
Capital expenditure	2	(4)	12
Depreciation and amortisation expense proportionately consolidated	199	177	26
Operating assets	$ (479)	$ (83)	$ (442)
Number of employees | Employee	124	159	187
Product group
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 47,018	$ 45,367	$ 42,835
Profit before taxation	24,713	22,132	19,319
Profit/(loss) after tax – attributable to owners of Rio Tinto	13,123	11,310	9,825
Capital expenditure	6,320	5,831	5,279
Depreciation and amortisation expense proportionately consolidated	4,773	4,960	4,622
Operating assets	$ 49,883	$ 46,632	$ 45,871
Number of employees | Employee	42,267	41,205	43,026
Central pension costs, share-based payments and insurance
Disclosure of operating segments [Line Items]
Profit before taxation	$ 72	$ 59	$ (128)
Profit/(loss) after tax – attributable to owners of Rio Tinto	81	60	(90)
Restructuring, project and one-off costs
Disclosure of operating segments [Line Items]
Profit before taxation	(133)	(183)	(272)
Profit/(loss) after tax – attributable to owners of Rio Tinto	(108)	(94)	(190)
Central costs
Disclosure of operating segments [Line Items]
Profit before taxation	(500)	(496)	(552)
Profit/(loss) after tax – attributable to owners of Rio Tinto	(418)	(550)	(410)
Exploration and evaluation
Disclosure of operating segments [Line Items]
Profit before taxation	(250)	(315)	(231)
Profit/(loss) after tax – attributable to owners of Rio Tinto	(216)	(231)	(193)
Net interest
Disclosure of operating segments [Line Items]
Profit/(loss) after tax – attributable to owners of Rio Tinto	(14)	(122)	(134)
Underlying EBITDA/earnings
Disclosure of operating segments [Line Items]
Profit before taxation	23,902	21,197	18,136
Profit/(loss) after tax – attributable to owners of Rio Tinto	12,448	10,373	8,808
Items excluded from underlying EBITDA/earnings
Disclosure of operating segments [Line Items]
Consolidated sales revenue
Profit before taxation	(395)	(722)	5,127
Profit/(loss) after tax – attributable to owners of Rio Tinto	(2,679)	(2,363)	4,830
Share of equity accounted unit sales and intra-subsidiary/equity accounted unit sales
Disclosure of operating segments [Line Items]
Adjustment for equity accounted units revenue	(2,407)	(2,202)	(2,313)
Depreciation and amortisation in equity accounted units	(576)	(653)	(650)
Taxation and finance items in equity accounted units	(443)	(296)	(372)
Capital expenditure	(255)	(456)	(500)
Depreciation and amortisation expense proportionately consolidated	(576)	(653)	(650)
Operating assets	$ 0	$ 0	$ 0
Number of employees | Employee	0	0	0
Other items
Disclosure of operating segments [Line Items]
Capital expenditure	$ 79	$ 64	$ 65
Depreciation and amortisation expense proportionately consolidated	82	77	43
Operating assets	$ (2,165)	$ (2,449)	$ (2,880)
Number of employees | Employee	5,207	4,802	4,432
Operating segments | Iron Ore
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 27,508	$ 24,075	$ 18,731
Profit before taxation	18,837	16,098	11,378
Profit/(loss) after tax – attributable to owners of Rio Tinto	11,398	9,638	6,531
Capital expenditure	2,941	1,741	1,302
Depreciation and amortisation expense proportionately consolidated	1,838	1,723	1,702
Operating assets	$ 16,650	$ 14,019	$ 14,653
Number of employees | Employee	11,883	10,981	10,661
Operating segments | Iron Ore | Intra-segment and other
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ (428)	$ 0	$ 0
Profit before taxation	(70)	0	0
Profit/(loss) after tax – attributable to owners of Rio Tinto	(53)	0	0
Capital expenditure	0	0	0
Depreciation and amortisation expense proportionately consolidated	0	0	0
Operating assets	$ (104)	$ 0	$ 0
Number of employees | Employee	0	0	0
Operating segments | Iron Ore | Evaluation projects/other
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 657	$ 123	$ 126
Profit before taxation	(32)	87	55
Profit/(loss) after tax – attributable to owners of Rio Tinto	(112)	(8)	53
Capital expenditure	0	0	0
Depreciation and amortisation expense proportionately consolidated	0	0	0
Operating assets	$ 338	$ 2	$ 2
Number of employees | Employee	10	0	0
Operating segments | Aluminium
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 9,314	$ 10,340	$ 12,191
Profit before taxation	2,152	2,285	3,095
Profit/(loss) after tax – attributable to owners of Rio Tinto	471	599	1,347
Capital expenditure	1,085	1,456	1,373
Depreciation and amortisation expense proportionately consolidated	1,191	1,312	1,122
Operating assets	$ 15,365	$ 16,030	$ 16,446
Number of employees | Employee	14,128	14,049	13,640
Operating segments | Aluminium | Intra-segment and other
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ (2,510)	$ (3,079)	$ (4,084)
Profit before taxation	6	30	(92)
Profit/(loss) after tax – attributable to owners of Rio Tinto	(159)	21	(69)
Capital expenditure	(1)	0	0
Depreciation and amortisation expense proportionately consolidated	1	0	(1)
Operating assets	$ 662	$ 780	$ 769
Number of employees | Employee	141	127	180
Operating segments | Aluminium | Bauxite
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 2,302	$ 2,490	$ 2,364
Profit before taxation	943	1,045	852
Profit/(loss) after tax – attributable to owners of Rio Tinto	434	498	466
Capital expenditure	142	387	953
Depreciation and amortisation expense proportionately consolidated	290	286	165
Operating assets	$ 2,593	$ 2,597	$ 2,494
Number of employees | Employee	2,853	2,940	2,676
Operating segments | Aluminium | Alumina
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 2,233	$ 2,720	$ 3,423
Profit before taxation	262	567	808
Profit/(loss) after tax – attributable to owners of Rio Tinto	92	247	390
Capital expenditure	228	282	218
Depreciation and amortisation expense proportionately consolidated	138	187	194
Operating assets	$ 2,294	$ 2,009	$ 2,721
Number of employees | Employee	2,383	2,269	2,009
Operating segments | Aluminium | Primary Metal
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 4,489	$ 4,940	$ 6,468
Profit before taxation	904	755	1,418
Profit/(loss) after tax – attributable to owners of Rio Tinto	169	40	595
Capital expenditure	602	658	595
Depreciation and amortisation expense proportionately consolidated	643	682	615
Operating assets	$ 9,361	$ 9,674	$ 9,306
Number of employees | Employee	6,282	6,357	6,497
Operating segments | Aluminium | Pacific Aluminium
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 1,944	$ 2,204	$ 2,541
Profit before taxation	112	(22)	148
Profit/(loss) after tax – attributable to owners of Rio Tinto	(6)	(137)	0
Capital expenditure	114	129	115
Depreciation and amortisation expense proportionately consolidated	119	154	149
Operating assets	$ 455	$ 970	$ 1,156
Number of employees | Employee	2,469	2,356	2,278
Operating segments | Aluminium | Integrated operations
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 8,458	$ 9,275	$ 10,712
Profit before taxation	2,227	2,375	3,134
Profit/(loss) after tax – attributable to owners of Rio Tinto	530	669	1,382
Capital expenditure	1,085	1,456	1,881
Depreciation and amortisation expense proportionately consolidated	1,191	1,309	1,122
Operating assets	$ 15,365	$ 16,030	$ 16,446
Number of employees | Employee	14,128	14,049	13,640
Operating segments | Aluminium | Other product group items
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 856	$ 1,065	$ 1,479
Profit before taxation	7	16	17
Profit/(loss) after tax – attributable to owners of Rio Tinto	(5)	10	11
Capital expenditure	0	0	(508)
Depreciation and amortisation expense proportionately consolidated	0	0	0
Operating assets	$ 0	$ 0	$ 0
Number of employees | Employee	0	0	0
Operating segments | Aluminium | Product group operations
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 9,314	$ 10,340	$ 12,191
Profit before taxation	2,234	2,391	3,151
Profit/(loss) after tax – attributable to owners of Rio Tinto	525	679	1,393
Capital expenditure	1,085	1,456	1,373
Depreciation and amortisation expense proportionately consolidated	1,191	1,309	1,122
Operating assets	$ 15,365	$ 16,030	$ 16,446
Number of employees | Employee	14,128	14,049	13,640
Operating segments | Aluminium | Evaluation projects/other
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 0	$ 0	$ 0
Profit before taxation	(82)	(106)	(56)
Profit/(loss) after tax – attributable to owners of Rio Tinto	(54)	(80)	(46)
Capital expenditure	0	0	0
Depreciation and amortisation expense proportionately consolidated	0	3	0
Operating assets	$ 0	$ 0	$ 0
Number of employees | Employee	0	0	0
Operating segments | Copper & Diamonds
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 5,428	$ 5,815	$ 6,468
Profit before taxation	2,172	2,073	2,776
Profit/(loss) after tax – attributable to owners of Rio Tinto	763	554	1,054
Capital expenditure	1,864	2,087	2,150
Depreciation and amortisation expense proportionately consolidated	1,153	1,320	1,317
Operating assets	$ 13,339	$ 12,010	$ 11,389
Number of employees | Employee	7,789	7,376	8,671
Operating segments | Copper & Diamonds | Product group operations
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 5,362	$ 5,800	$ 6,468
Profit before taxation	2,523	2,385	3,043
Profit/(loss) after tax – attributable to owners of Rio Tinto	968	726	1,203
Capital expenditure	1,859	2,086	2,139
Depreciation and amortisation expense proportionately consolidated	1,149	1,317	1,312
Operating assets	$ 13,147	$ 11,858	$ 11,260
Number of employees | Employee	7,630	7,226	8,525
Operating segments | Copper & Diamonds | Diamonds
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 459	$ 619	$ 695
Profit before taxation	83	151	301
Profit/(loss) after tax – attributable to owners of Rio Tinto	9	(21)	118
Capital expenditure	25	38	64
Depreciation and amortisation expense proportionately consolidated	60	144	118
Operating assets	$ (7)	$ 195	$ 267
Number of employees | Employee	885	940	967
Operating segments | Copper & Diamonds | Evaluation projects/other
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 66	$ 15	$ 0
Profit before taxation	(351)	(312)	(267)
Profit/(loss) after tax – attributable to owners of Rio Tinto	(205)	(172)	(149)
Capital expenditure	5	1	11
Depreciation and amortisation expense proportionately consolidated	4	3	5
Operating assets	$ 192	$ 152	$ 129
Number of employees | Employee	159	150	146
Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 5,014	$ 5,150	$ 5,451
Profit before taxation	1,646	1,762	2,140
Profit/(loss) after tax – attributable to owners of Rio Tinto	577	611	995
Capital expenditure	428	551	442
Depreciation and amortisation expense proportionately consolidated	392	428	455
Operating assets	$ 4,879	$ 4,529	$ 3,696
Number of employees | Employee	8,343	8,640	9,867
Operating segments | Energy & Minerals | Product group operations
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 4,962	$ 5,095	$ 5,391
Profit before taxation	1,756	1,870	2,204
Profit/(loss) after tax – attributable to owners of Rio Tinto	670	707	1,038
Capital expenditure	429	552	442
Depreciation and amortisation expense proportionately consolidated	392	428	455
Operating assets	$ 4,830	$ 4,472	$ 3,640
Number of employees | Employee	8,197	8,513	9,764
Operating segments | Energy & Minerals | Uranium
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 303	$ 375	$ 415
Profit before taxation	24	55	18
Profit/(loss) after tax – attributable to owners of Rio Tinto	6	25	(4)
Capital expenditure	0	5	8
Depreciation and amortisation expense proportionately consolidated	0	3	4
Operating assets	$ (71)	$ (363)	$ (406)
Number of employees | Employee	364	857	1,324
Operating segments | Energy & Minerals | Evaluation projects/other
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 52	$ 55	$ 60
Profit before taxation	(96)	(96)	(49)
Profit/(loss) after tax – attributable to owners of Rio Tinto	(87)	(91)	(36)
Capital expenditure	1	0	0
Depreciation and amortisation expense proportionately consolidated	0	0	0
Operating assets	$ 33	$ 37	$ 41
Number of employees | Employee	77	53	33
Inter-segment transactions
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ (264)	$ (31)	$ (15)
Profit before taxation	(94)	(9)	0
Profit/(loss) after tax – attributable to owners of Rio Tinto	(32)	(3)	0
Operating assets	129	127	129
Oyu Tolgoi and Turquoise Hill | Operating segments | Copper & Diamonds
Disclosure of operating segments [Line Items]
Consolidated sales revenue	1,078	1,166	1,180
Profit before taxation	390	357	375
Profit/(loss) after tax – attributable to owners of Rio Tinto	160	25	69
Capital expenditure	1,038	1,289	1,284
Depreciation and amortisation expense proportionately consolidated	189	208	219
Operating assets	$ 8,111	$ 6,780	$ 6,072
Number of employees | Employee	3,450	3,152	2,863
Grasberg joint venture | Operating segments | Copper & Diamonds
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 0	$ 0	$ 457
Profit before taxation	0	0	281
Profit/(loss) after tax – attributable to owners of Rio Tinto	0	0	217
Capital expenditure	0	0	171
Depreciation and amortisation expense proportionately consolidated	0	0	30
Operating assets	$ 0	$ 0	$ 0
Number of employees | Employee	0	0	1,615
Pilbara | Operating segments | Iron Ore
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 27,027	$ 23,681	$ 18,359
Profit before taxation	18,896	15,936	11,267
Profit/(loss) after tax – attributable to owners of Rio Tinto	11,551	9,619	6,460
Capital expenditure	2,919	1,720	1,288
Depreciation and amortisation expense proportionately consolidated	1,819	1,704	1,682
Operating assets	$ 16,253	$ 13,865	$ 14,486
Number of employees | Employee	11,522	10,634	10,422
Dampier Salt | Operating segments | Iron Ore
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary	68.40%
Consolidated sales revenue	$ 252	$ 271	$ 246
Profit before taxation	43	75	56
Profit/(loss) after tax – attributable to owners of Rio Tinto	12	27	18
Capital expenditure	22	21	14
Depreciation and amortisation expense proportionately consolidated	19	19	20
Operating assets	$ 163	$ 152	$ 165
Number of employees | Employee	351	347	239
Rio Tinto Kennecott | Operating segments | Copper & Diamonds
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary	100.00%
Consolidated sales revenue	$ 1,529	$ 1,879	$ 1,862
Profit before taxation	588	843	785
Profit/(loss) after tax – attributable to owners of Rio Tinto	149	397	293
Capital expenditure	618	444	318
Depreciation and amortisation expense proportionately consolidated	472	457	427
Operating assets	$ 2,317	$ 2,012	$ 1,864
Number of employees | Employee	2,171	2,066	1,993
Escondida | Operating segments | Copper & Diamonds
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary	30.00%
Consolidated sales revenue	$ 2,296	$ 2,136	$ 2,274
Profit before taxation	1,462	1,034	1,301
Profit/(loss) after tax – attributable to owners of Rio Tinto	650	325	506
Capital expenditure	178	315	302
Depreciation and amortisation expense proportionately consolidated	428	508	518
Operating assets	$ 2,726	$ 2,871	$ 3,057
Number of employees | Employee	1,124	1,068	1,087
Rio Tinto Coal Australia | Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 0	$ 0	$ 989
Profit before taxation	0	0	893
Profit/(loss) after tax – attributable to owners of Rio Tinto	0	0	591
Capital expenditure	0	0	32
Depreciation and amortisation expense proportionately consolidated	0	0	34
Operating assets	$ 0	$ 0	$ (837)
Number of employees | Employee	0	0	1,005
Iron Ore Company of Canada
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 2,269	$ 2,014
Profit/(loss) after tax – attributable to owners of Rio Tinto	359	319
Equity attributable to owners of Rio Tinto	$ 1,144	1,018
Iron Ore Company of Canada | Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary	58.70%
Consolidated sales revenue	$ 2,444	2,189	$ 1,583
Profit before taxation	1,130	1,024	586
Profit/(loss) after tax – attributable to owners of Rio Tinto	383	332	166
Capital expenditure	243	255	189
Depreciation and amortisation expense proportionately consolidated	170	172	154
Operating assets	$ 1,009	$ 803	$ 975
Number of employees | Employee	2,716	2,617	2,397
Rio Tinto Iron & Titanium | Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 1,651	$ 1,938	$ 1,782
Profit before taxation	476	611	510
Profit/(loss) after tax – attributable to owners of Rio Tinto	216	254	174
Capital expenditure	144	249	169
Depreciation and amortisation expense proportionately consolidated	173	193	201
Operating assets	$ 3,390	$ 3,507	$ 3,390
Number of employees | Employee	4,151	4,115	4,058
Rio Tinto Borates | Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary	100.00%
Consolidated sales revenue	$ 564	$ 593	$ 622
Profit before taxation	126	180	197
Profit/(loss) after tax – attributable to owners of Rio Tinto	65	96	111
Capital expenditure	42	43	44
Depreciation and amortisation expense proportionately consolidated	49	60	62
Operating assets	$ 502	$ 525	$ 518
Number of employees | Employee	966	924	980
Simandou iron ore project | Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Consolidated sales revenue	$ 0	$ 0	$ 0
Profit before taxation	(14)	(12)	(15)
Profit/(loss) after tax – attributable to owners of Rio Tinto	(6)	(5)	(7)
Capital expenditure	(2)	(1)	0
Depreciation and amortisation expense proportionately consolidated	0	0	0
Operating assets	$ 16	$ 20	$ 15
Number of employees | Employee	69	74	70

Rio Tinto financial informati_4

Rio Tinto financial information by business unit Rio Tinto financial information by business unit - Schedule of financial information by business unit (Parenthetical) (Detail) - USD ($) $ in Millions	Jul. 16, 2019	Aug. 01, 2018	Jun. 01, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of operating segments [Line Items]
Proportion of net beneficial interest				53.00%
Net beneficial interest held percentage				35.00%
Net beneficial interest held percentage as owned subsidiary				100.00%
Proceeds from sale of surplus land					$ 508
Proceeds from issue of equity to non-controlling interests				$ 129	101	$ 85
Operating assets				47,718	$ 44,183	43,431
Capital expenditure percentage of subsidiaries					100.00%
Consolidated sales revenue				44,611	$ 43,165	40,522
Profit before taxation				17,142	11,767	18,200
Profit/(loss) after tax – attributable to owners of Rio Tinto				9,769	8,010	13,638
Restatement Adjustment For Legacy Alumina Contracts
Disclosure of operating segments [Line Items]
Profit before taxation					218	457
Profit/(loss) after tax – attributable to owners of Rio Tinto					171	355
Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Operating assets				4,879	4,529	3,696
Consolidated sales revenue				5,014	5,150	5,451
Profit before taxation				1,646	1,762	2,140
Profit/(loss) after tax – attributable to owners of Rio Tinto				577	611	995
Operating segments | Aluminium
Disclosure of operating segments [Line Items]
Operating assets				15,365	16,030	16,446
Consolidated sales revenue				9,314	10,340	12,191
Profit before taxation				2,152	2,285	3,095
Profit/(loss) after tax – attributable to owners of Rio Tinto				471	599	1,347
Operating segments | Aluminium | Intra-segment and other
Disclosure of operating segments [Line Items]
Operating assets				662	780	769
Consolidated sales revenue				(2,510)	(3,079)	(4,084)
Profit before taxation				6	30	(92)
Profit/(loss) after tax – attributable to owners of Rio Tinto				(159)	21	(69)
Australia
Disclosure of operating segments [Line Items]
Consolidated sales revenue				745	737	720
Bauxite & alumina | Operating segments | Aluminium | Intra-segment and other
Disclosure of operating segments [Line Items]
Operating assets				7	27	20
Consolidated sales revenue				722	825	861
Profit before taxation				31	10	7
Profit/(loss) after tax – attributable to owners of Rio Tinto				21	7	5
Bauxite | Restatement Adjustment For Internal Shipping
Disclosure of operating segments [Line Items]
Consolidated sales revenue					31	40
Profit before taxation					76	62
Profit/(loss) after tax – attributable to owners of Rio Tinto					57	54
Bauxite | Operating segments | Aluminium
Disclosure of operating segments [Line Items]
Operating assets				2,593	2,597	2,494
Consolidated sales revenue				2,302	2,490	2,364
Profit before taxation				943	1,045	852
Profit/(loss) after tax – attributable to owners of Rio Tinto				434	498	466
Alumina | Restatement Adjustment For Internal Shipping
Disclosure of operating segments [Line Items]
Consolidated sales revenue					63	83
Profit before taxation					157	128
Profit/(loss) after tax – attributable to owners of Rio Tinto					117	111
Alumina | Operating segments | Aluminium
Disclosure of operating segments [Line Items]
Operating assets				2,294	2,009	2,721
Consolidated sales revenue				2,233	2,720	3,423
Profit before taxation				262	567	808
Profit/(loss) after tax – attributable to owners of Rio Tinto				$ 92	$ 247	390
Hope Downs Joint Venture
Disclosure of operating segments [Line Items]
Proportion of ownership interest in joint venture				50.00%
Robe River
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary				65.00%
Proportion of net beneficial interest				53.00%
Non-controlling interest (%)				12.00%
Freeport-McMoRan Inc [Member]
Disclosure of operating segments [Line Items]
Percentage of material mined					40.00%
Diavik
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary					60.00%
Proportion of ownership interest in joint venture				60.00%
Hail Creek
Disclosure of operating segments [Line Items]
Ownership interest in joint venture disposed		82.00%
Hail Creek | Australia
Disclosure of operating segments [Line Items]
Proceeds from disposal of ownership in joint venture		$ 1,700
Kestrel Underground Coal Mine
Disclosure of operating segments [Line Items]
Proportion of ownership interest in joint venture		80.00%
Kestrel Underground Coal Mine | Australia
Disclosure of operating segments [Line Items]
Proceeds from disposal of ownership in joint venture		$ 2,250
Winchester South
Disclosure of operating segments [Line Items]
Proportion of ownership interest in joint venture			75.00%
Proceeds from disposal of ownership in joint venture			$ 200
Valeria
Disclosure of operating segments [Line Items]
Ownership interest in joint venture disposed		71.20%
30 Percent [Member] | Robe River
Disclosure of operating segments [Line Items]
Net beneficial interest held percentage				30.00%
35 Percent [Member] | Robe River
Disclosure of operating segments [Line Items]
Net beneficial interest held percentage as owned subsidiary				60.00%
Hamersley Iron Pty Limited
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary				100.00%
Hamersley Iron Pty Limited | Ordinary
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary				100.00%
Oyu Tolgoi | Turquoise Hill Resources Ltd
Disclosure of operating segments [Line Items]
Percentage of share class held in subsidiaries					50.80%
Oyu Tolgoi | Turquoise Hill Resources Ltd | Oyo Tolgoi Copper-Gold Mine
Disclosure of operating segments [Line Items]
Percentage of share class held in subsidiaries					66.00%
Argyle Diamonds Limited
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary					100.00%
Argyle Diamonds Limited | Ordinary
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary				100.00%
Rio Tinto Coal Australia | Operating segments | Energy & Minerals
Disclosure of operating segments [Line Items]
Operating assets				$ 0	$ 0	(837)
Consolidated sales revenue				0	0	989
Profit before taxation				0	0	893
Profit/(loss) after tax – attributable to owners of Rio Tinto				$ 0	$ 0	$ 591
Rio Tinto Fer et Titane Inc.
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary					100.00%
QIT Madagascar Minerals SA
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary					80.00%
Richards Bay Minerals
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary					74.00%
Energy Resources of Australia Ltd | Ordinary
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary				86.33%	68.60%
Non-controlling interest (%)				13.67%
Rossing Uranium Limited
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary	68.62%
Simfer Jersey Limited | Ordinary
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary				53.00%	53.00%
Non-controlling interest (%)				47.00%
Simfer S.A.
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary				85.00%	85.00%
Non-controlling interest (%)					45.05%
Gove Alumina Refinery and Rio Tinto Marine [Member]
Disclosure of operating segments [Line Items]
Ownership percentage in subsidiary					100.00%