Earnings Per Share ("EPS") (Tables)

6 Months Ended

Mar. 29, 2015

Earnings Per Share ("EPS")

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

	Three Months Ended				Six Months Ended
	March 29, 2015		March 30, 2014		March 29, 2015		March 30, 2014
	(in thousands, except per share data)
Net income attributable to Tetra Tech	$	19,017	$	31,709	$	44,592	$	59,023
Weighted-average common shares outstanding – basic	61,153		64,835		61,816		64,670
Effect of dilutive stock options and unvested restricted stock	570		875		615		847
Weighted-average common stock outstanding – diluted	61,723		65,710		62,431		65,517
Earnings per share attributable to Tetra Tech:
Basic	$	0.31	$	0.49	$	0.72	$	0.91
Diluted	$	0.31	$	0.48	$	0.71	$	0.90