Earnings Per Share

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Earnings per Share

following table presents the calculation of basic and diluted earnings per share:

	Year Ended December 31,
(MILLIONS OF DOLLARS AND SHARES, EXCEPT PER SHARE DATA)	2020		2019		2018
Numerator
Net income before allocation to noncontrolling interests	$	1,636	$	1,500	$	1,424
Less: net loss attributable to noncontrolling interests	(2)		—		(4)
Net income attributable to Zoetis Inc.	$	1,638	$	1,500	$	1,428
Denominator
Weighted-average common shares outstanding	475.502		478.128		483.063
Common stock equivalents: stock options, RSUs, DSUs and PSUs	3.067		3.659		3.835
Weighted-average common and potential dilutive shares outstanding	478.569		481.787		486.898
Earnings per share attributable to Zoetis Inc. stockholders—basic	$	3.44	$	3.14	$	2.96
Earnings per share attributable to Zoetis Inc. stockholders—diluted	$	3.42	$	3.11	$	2.93

The number of stock options outstanding under the company's Equity Plan that were excluded from the computation of diluted earnings per share, as the effect would have been antidilutive, were de minimis for the years ended December 31, 2020, 2019 and 2018.