NET INCOME PER SHARE

The following table presents the computation of basic and diluted net income per share attributable to Intuitive Surgical, Inc. for the three and nine months ended September 30, 2018, and 2017 (in millions, except per share amounts):



	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Numerator:
Net income attributable to Intuitive Surgical, Inc.	$	292.5	$	298.6	$	835.4	$	702.4
Denominator:
Weighted average shares outstanding used in basic calculation	114.0		111.8		113.4		111.6
Add: dilutive effect of potential common shares	5.2		5.0		5.2		4.3
Weighted average shares outstanding used in diluted calculation	119.2		116.8		118.6		115.9
Net income per share attributable to Intuitive Surgical, Inc.:
Basic	$	2.57	$	2.67	$	7.37	$	6.29
Diluted	$	2.45	$	2.56	$	7.04	$	6.06

Share-based compensation awards of approximately 0.4 million and 0.2 million shares for the three months ended September 30, 2018, and 2017, respectively, and approximately 0.3 million and 0.4 million shares for the nine months ended September 30, 2018, and 2017, respectively, were outstanding, but were not included in the computation of diluted net income per share attributable to Intuitive Surgical, Inc. common stockholders because the effect of including such shares would have been anti-dilutive in the periods presented.