MPLX (MPLX) 8-K Other Events

Exhibit 12.1

MPLX LP

Computation of Ratio of Earnings to Fixed Charges

TOTAL ENTERPRISE BASIS - Unaudited

(In millions)

	For the Nine Months Ended		For the Years Ended December 31,
	September 30, 2016		2015		2014		2013		2012		2011
Portion of rentals representing interest	$	12	$	7	$	6	$	6	$	5	$	2
Capitalized interest		21		5		1		1		1		1
Other interest and fixed charges		191		40		4		—		—		—
Preference security dividend requirements		28		—		—		—		—		—
Total fixed charges (A)	$	252	$	52	$	11	$	7	$	6	$	3
Earnings-pretax income with applicable adjustments (B)	$	502	$	310	$	252	$	220	$	211	$	166
Ratio of (B) to (A)		2.0		6.0		22.9		31.4		35.2		55.3