Septic Tank Size Calculator
Tank size, drainfield area, and pump-out interval.
Tank size needed
1,250
gallons
Daily flow estimate
2,813
gallons
Drainfield area
4,219
sq ft min
Pump-out interval
3
years
Sizing follows the standard "750 gallons per bedroom" rule with a minimum 1000 gallon tank. Local codes (esp. in MA, NJ, PA) often require larger. Drainfield sizing also depends on soil percolation rate. Always work with a licensed designer for installation.
About
Enter bedrooms and residents. Get a recommended tank size (per IPC standard 750 gallons per bedroom, minimum 1000), daily flow estimate, drainfield area, and how often to pump.
How to use
- Enter bedroom count and residents.
- Toggle garbage disposal and fixture efficiency.
FAQ
Why bedrooms instead of bathrooms?+
Bedrooms are the regulatory standard because they predict occupancy. Bathrooms only matter for instantaneous flow, not tank capacity.