Exhibit 12.1

Marathon Petroleum Corporation

Computation of Ratio of Earnings to Fixed Charges

TOTAL ENTERPRISE BASIS – Unaudited

(In millions)

	For the Years Ended December 31,
	2012		2011		2010		2009		2008
Portion of rentals representing interest	$	46	$	41	$	45	$	41	$	43
Capitalized interest		101		112		83		78		60
Other interest and fixed charges		90		60		1		1		1
Total fixed charges (A)	$	237	$	213	$	129	$	120	$	104
Earnings-pretax income with applicable adjustments (B)	$	5,423	$	3,848	$	1,063	$	748	$	1,986
Ratio of (B) to (A)		22.9		18.1		8.2		6.2		19.1