Earnings per Share ("EPS") (Tables)

3 Months Ended

Dec. 27, 2020

Earnings Per Share [Abstract]

Schedule of number of weighted-average shares used to compute basic and diluted EPS

The following table presents the number of weighted-average shares used to compute basic and diluted EPS:

	Three Months Ended
	December 27, 2020		December 29, 2019
	(in thousands, except per share data)
Net income attributable to Tetra Tech	$	52,436	$	47,310
Weighted-average common shares outstanding – basic	53,927		54,560
Effect of dilutive stock options and unvested restricted stock	710		878
Weighted-average common shares outstanding – diluted	54,637		55,438
Earnings per share attributable to Tetra Tech:
Basic	$	0.97	$	0.87
Diluted	$	0.96	$	0.85