Find a planning estimate for the right septic tank size for your home, based on bedrooms, occupants, soil type and garbage disposal use. No signup, no cost.
Septic Tank Size Calculator
Find a planning estimate for your home in under a minute.
How many bedrooms?
Bedrooms drive the code minimum — even if fewer people live there. For 7+ bedrooms, choose Custom and enter the number.
Planning estimate only. Method: bedroom minimums commonly seen in many US codes (1 bed: 750 gal, 2 bed: 750–1,000 gal, 3 bed: 1,000 gal, 4 bed: 1,250 gal, 5 bed: 1,500 gal, 6 bed: 1,750 gal; for 7+ bedrooms, add 250 gal per bedroom over 6), checked against a 150 gallons per bedroom per day design flow. Drainfield size needs a percolation test. County and state rules govern.
Disclaimer: All results are estimates for planning only. County and state rules govern — check with your local authority.