Earnings Per Share ("EPS") (Tables)

6 Months Ended

Mar. 27, 2016

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 27, 2016		March 29, 2015		March 27, 2016		March 29, 2015
	(in thousands, except per share data)
Net income attributable to Tetra Tech	$	3,744	$	19,017	$	26,983	44,592
Weighted-average common shares outstanding — basic	58,451		61,153		58,819		61,816
Effect of dilutive stock options and unvested restricted stock	680		570		708		615
Weighted-average common stock outstanding — diluted	59,131		61,723		59,527		62,431
Earnings per share attributable to Tetra Tech:
Basic	$	0.06	$	0.31	$	0.46	$	0.72
Diluted	$	0.06	$	0.31	$	0.45	$	0.71