Earnings per Share ("EPS") (Tables)

9 Months Ended

Jun. 30, 2024

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				Nine Months Ended
	June 30, 2024		July 2, 2023		June 30, 2024		July 2, 2023
Net income attributable to Tetra Tech	$	85,810	$	60,235	$	237,228	$	219,771
Weighted-average common shares outstanding – basic	53,515		53,231		53,451		53,188
Effect of dilutive stock options and unvested restricted stock	433		422		415		427
Shares issuable assuming conversion of convertible notes	104		—		35		—
Weighted-average common shares outstanding – diluted	54,052		53,653		53,901		53,615
Earnings per share attributable to Tetra Tech:
Basic	$	1.60	$	1.13	$	4.44	$	4.13
Diluted	$	1.59	$	1.12	$	4.40	$	4.10