Septic Tank Calculator

Determine septic tank size, drain field requirements, and pump-out schedule.

Average: 60-75 gal/person/day
Minimum Tank Size
0
gallons
Daily Flow
0 gal
Drain Field Area
0 sq ft
Pump-Out Frequency
0 years
Trench Length
0 ft
3 ft wide trenches
Recommended Tank
--

How to Size a Septic Tank

Min tank size: Based on bedrooms per local code (usually 1000 gal for 3 BR)

Daily flow: Occupants x Gallons per person per day

Drain field: Daily flow / Soil application rate (gal/sq ft/day)

Standard Tank Sizes by Bedroom

  • 1-2 bedrooms: 750-1,000 gallon tank
  • 3 bedrooms: 1,000 gallon tank (most common)
  • 4 bedrooms: 1,250 gallon tank
  • 5-6 bedrooms: 1,500+ gallon tank

Maintenance Tips

  • Pump tank every 3-5 years for a family of 4
  • Do not drive or park over the drain field
  • Avoid flushing non-biodegradable items
  • Spread laundry loads throughout the week

Related Calculators