Septic Tank Size Calculator

Right-size a septic system before you dig. Enter the number of bedrooms to get the recommended tank capacity and an estimate of the leach field area.

rooms
people
Leave 0 to estimate 2 people per bedroom.

🏠 Bedroom rule

Local codes usually size the tank by bedroom count — 3 BR = 1,000 gal.

🔋 Retention time

Sizes for a 1-2 day wastewater retention inside the tank.

🌾 Soil aware

Leach field area depends on how fast your soil drains.

⚠️ Not a permit

Always check your local health department requirements.

More home tools

Plan the utilities too.