Earnings per Share

9 Months Ended

Sep. 30, 2022

Basic and diluted shares outstanding used in our earnings per share calculation are calculated as follows:


	For the Three Months Ended September 30,				For the Nine Months Ended September 30,
(In millions)	2022		2021		2022		2021
Numerator:
Net income attributable to Biogen Inc.	$	1,134.7	$	329.2	$	2,496.5	$	1,187.9
Denominator:
Weighted average number of common shares outstanding	144.4		148.0		145.8		149.9
Effect of dilutive securities:

Time-vested restricted stock units	0.3		0.4		0.3		0.2
Market stock units	—		0.1		—		0.1
Performance stock units settled in stock	0.1		0.1		0.1		0.1
Dilutive potential common shares	0.4		0.6		0.4		0.4
Shares used in calculating diluted earnings per share	144.8		148.6		146.2		150.3

Amounts excluded from the calculation of net income per diluted share because their effects were anti-dilutive were insignificant.