Tetra Tech, Inc. revenue for the last year amounted to 4.32 B USD, the most of which — 2.79 B USD — came from its highest performing source at the moment, Commercial/International Services Group, the year earlier bringing 2.42 B USD. The greatest contribution to the revenue figure was made by United States — last year it brought Tetra Tech, Inc. 3.20 B USD, and the year before that — 2.86 B USD.