| Revenue | 5,198.68a | 4,522.55a | 3,504.05a |
| Subcontractor costs | -876.82a | -771.46a | -668.47a |
| Other costs of revenue | -3,455.42a | -3,026.06a | -2,260.02a |
| Gross profit | 866.44a | 725.03a | 575.56a |
| Selling, general and administrative expenses | -356.02a | -305.11a | -234.78a |
| Acquisition and integration expenses | -7.14a | -33.17a | 0a |
| Right-of-use operating lease asset impairment | 0a | -16.39a | 0a |
| Contingent consideration - fair value adjustments | -2.54a | -12.26a | -0.33a |
| Income from operations | 500.74a | 358.11a | 340.45a |
| Interest income | 7.29a | 5.9a | 1.78a |
| Interest expense | -44.56a | -52.44a | -13.36a |
| Other non-operating income | 0a | 89.4a | 19.9a |
| Income before income tax expense | 463.47a | 400.98a | 348.77a |
| Income tax expense | -130.02a | -127.53a | -85.6a |
| Net income | 333.44a | 273.45a | 263.16a |
| Net income attributable to noncontrolling interests | -0.06a | -0.03a | -0.04a |
| Net income attributable to Tetra Tech | 333.38a | 273.42a | 263.13a |