Earnings Per Share ("EPS") (Tables)

6 Months Ended

Mar. 31, 2013

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 31, 2013		April 1, 2012		March 31, 2013		April 1, 2012
	(in thousands, except per share data)
Net income attributable to Tetra Tech	$	24,820	$	22,284	$	51,043	$	44,894
Weighted-average common shares outstanding – basic	64,551		63,072		64,376		62,846
Effect of dilutive stock options and unvested restricted stock	921		745		832		651
Weighted-average common stock outstanding – diluted	65,472		63,817		65,208		63,497
Earnings per share attributable to Tetra Tech:
Basic	$	0.38	$	0.35	$	0.79	$	0.71
Diluted	$	0.38	$	0.35	$	0.78	$	0.71