MPLX (MPLX) 10-K 2017 FY Annual report

Exhibit 12.1

MPLX LP

Computation of Ratio of Earnings to Fixed Charges

TOTAL ENTERPRISE BASIS - Unaudited

(In millions)

	For the Years Ended December 31,
	2017		2016		2015		2014		2013
Portion of rentals representing interest(1)	$	18	$	16	$	7	$	6	$	6
Capitalized interest	32		28		5		1		1
Other interest and fixed charges(2)	343		254		40		4		—
Total fixed charges (A)	$	393	$	298	$	52	$	11	$	7
Preferred dividend requirements	$	65	$	41	$	—	$	—	$	—
Ratio of income (loss) before provision for taxes to net income (loss)	1.0		1.0		1.0		1.0		1.0
Total preferred dividends	$	65	$	41	$	—	$	—	$	—
Combined fixed charges and preferred dividends (B)	$	458	$	339	$	52	$	11	$	7
Earnings-pretax income with applicable adjustments (C)	$	1,365	$	916	$	394	$	252	$	220
Ratio of (C) to (A)	3.5		3.1		7.6		22.9		31.4
Ratio of (C) to (B)	3.0		2.7		7.6		22.9		31.4

⁽¹⁾ Primarily related to interest incurred on operating leases.

⁽²⁾ Includes amortization of discounts on senior notes