Tetra Tech, Inc. revenue for the last year amounted to 3.75 B USD, the most of which — 2.42 B USD — came from its highest performing source at the moment, Commercial/International Services Group, the year earlier bringing 1.74 B USD. The greatest contribution to the revenue figure was made by United States — last year it brought Tetra Tech, Inc. 2.86 B USD, and the year before that — 2.42 B USD.