Earnings per Share

9 Months Ended

Sep. 30, 2019

EARNINGS PER SHARE

We compute basic earnings per share by dividing net income attributable to MPC less income allocated to participating securities by the weighted average number of shares of common stock outstanding. Since MPC grants certain incentive compensation awards to employees and non-employee directors that are considered to be participating securities, we have calculated our earnings per share using the two-class method. Diluted income per share assumes exercise of certain stock-based compensation awards, provided the effect is not anti-dilutive.



	Three Months Ended September 30,				Nine Months Ended September 30,
(In millions, except per share data)	2019		2018		2019		2018
Basic earnings per share:
Allocation of earnings:
Net income attributable to MPC	$	1,095	$	737	$	2,194	$	1,829
Income allocated to participating securities	—		—		1		1
Income available to common stockholders – basic	$	1,095	$	737	$	2,193	$	1,828
Weighted average common shares outstanding	656		451		663		462
Basic earnings per share	$	1.67	$	1.63	$	3.31	$	3.96
Diluted earnings per share:
Allocation of earnings:
Net income attributable to MPC	$	1,095	$	737	$	2,194	$	1,829
Income allocated to participating securities	—		—		1		1
Income available to common stockholders – diluted	$	1,095	$	737	$	2,193	$	1,828
Weighted average common shares outstanding	656		451		663		462
Effect of dilutive securities	4		5		5		4
Weighted average common shares, including dilutive effect	660		456		668		466
Diluted earnings per share	$	1.66	$	1.62	$	3.28	$	3.92

The following table summarizes the shares that were anti-dilutive and, therefore, were excluded from the diluted share calculation.



	Three Months Ended September 30,		Nine Months Ended September 30,
(In millions)	2019	2018	2019	2018
Shares issuable under stock-based compensation plans	4	—	3	—