Weighted-Average Shares

9 Months Ended

Sep. 30, 2018

Weighted-average shares were calculated as follows (in thousands):



	Three-months Ended		Nine-months Ended
	September 30, 2018	October 1, 2017	September 30, 2018	October 1, 2017
Basic weighted-average common shares outstanding	172,189	173,234	172,613	173,052
Effect of dilutive stock options	5,056	6,120	5,408	6,072
Weighted-average common and common-equivalent shares outstanding	177,245	179,354	178,021	179,124

Stock options to purchase 2,796,000 and 2,353,000 shares of common stock, on a weighted-average basis, were outstanding during the three-month and nine-month periods ended September 30, 2018, respectively, and 466,000 and 3,108,000 for the same periods in 2017, but were not included in the calculation of dilutive net income per share because they were anti-dilutive.