Septic Tank Size Estimator

Estimate a baseline residential septic tank size from bedrooms and expected daily flow.

Estimated result

How this calculator works

Estimate a baseline residential septic tank size from bedrooms and expected daily flow.

Baseline volume = bedrooms × daily flow per bedroom × storage days

Planning note

Results are estimates. Confirm local plumbing codes, product specifications and licensed-professional requirements before construction or safety-critical work.