Earnings per Share ("EPS") (Tables)

3 Months Ended

Dec. 31, 2023

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 (in thousands, except per share data):

	Three Months Ended
	December 31, 2023		January 1, 2023
Net income attributable to Tetra Tech	$	74,972	$	116,706
Weighted-average common shares outstanding – basic	53,317		53,069
Effect of dilutive stock options and unvested restricted stock	421		460
Weighted-average common shares outstanding – diluted	53,738		53,529
Earnings per share attributable to Tetra Tech:
Basic	$	1.41	$	2.20
Diluted	$	1.40	$	2.18