Earnings per Share

12 Months Ended

Dec. 31, 2023


Note 15:			Earnings per Share

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


	For the Years Ended December 31,
(In millions)	2023		2022		2021
Numerator:
Net income attributable to Biogen Inc.	$	1,161.1	$	3,046.9	$	1,556.1
Denominator:
Weighted average number of common shares outstanding	144.7		145.3		149.1
Effect of dilutive securities:

Time-vested restricted stock units	0.7		0.5		0.3
Market stock units	—		0.1		0.1
Performance stock units settled in stock	0.2		0.1		0.1
Dilutive potential common shares	0.9		0.7		0.5
Shares used in calculating diluted earnings per share	145.6		146.0		149.6

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

Earnings per share for the years ended December 31, 2022 and 2021, reflects the repurchase of approximately 3.6 million shares and 6.0 million shares of our common stock, respectively, under our share repurchase programs. There were no share repurchases of our common stock during the year ended December 31, 2023. For additional information on our share repurchase programs, please read Note 14, Equity, to these consolidated financial statements.