Tetra Tech, Inc. (TTEK)

Tetra Tech Employees

Tetra Tech had 25,000 employees as of September 28, 2025. The number of employees decreased by 5,000 or -16.67% compared to the previous year.

• Employees: 25,000
• Change (1Y): -5,000
• Growth (1Y): -16.67%
• Revenue / Employee: $184,694
• Profits / Employee: $9,909
• Market Cap: 8.81B

Employees History

Date	Employees	Change	Growth
Sep 28, 2025	25,000	-5,000	-16.67%
Sep 29, 2024	30,000	3,000	11.11%
Oct 1, 2023	27,000	6,000	28.57%
Oct 2, 2022	21,000	0	-
Oct 3, 2021	21,000	1,000	5.00%
Sep 27, 2020	20,000	0	-
Sep 29, 2019	20,000	3,000	17.65%
Sep 30, 2018	17,000	1,000	6.25%
Oct 1, 2017	16,000	0	-
Oct 2, 2016	16,000	3,000	23.08%
Sep 27, 2015	13,000	-1,000	-7.14%
Sep 28, 2014	14,000	0	-
Sep 29, 2013	14,000	1,000	7.69%
Sep 30, 2012	13,000	0	-
Oct 2, 2011	13,000	1,000	8.33%
Oct 3, 2010	12,000	2,000	20.00%
Sep 27, 2009	10,000	800	8.70%
Sep 28, 2008	9,200	1,400	17.95%
Sep 30, 2007	7,800	500	6.85%
Oct 1, 2006	7,300	-400	-5.19%
Oct 2, 2005	7,700	-900	-10.47%
Oct 3, 2004	8,600	-300	-3.37%
Sep 28, 2003	8,900	1,408	18.79%
Sep 29, 2002	7,492	92	1.24%
Sep 30, 2001	7,400	799	12.10%
Oct 1, 2000	6,601	1,158	21.28%
Oct 3, 1999	5,443	1,781	48.63%
Oct 4, 1998	3,662	1,400	61.89%
Sep 28, 1997	2,262	373	19.75%
Sep 29, 1996	1,889	-	-

Sources: Annual number of employees according to filings submitted to the U.S. Securities and Exchange Commission (SEC). Data is also manually gathered from company press releases, IPO filings, and other official sources.