OhMyCalc

Septic Tank Calculator

Calculate the required septic tank size and drain field area based on bedrooms, occupants, and usage.

How to Use the Septic Tank Calculator

  1. Enter the number of bedrooms.
  2. Enter the number of occupants.
  3. Select the usage level.
  4. Click Calculate for tank size and drain field area.

حالات الاستخدام

الصيغة

Tank = max(bedrooms × 500, occupants × 200) L × usage factor. Drain field = occupants × 12–18 m².

الأسئلة الشائعة

Why size by bedrooms?
Building codes often size septic systems by bedroom count as a proxy for maximum occupancy.
What is a drain field?
A drain field (leach field) is the area where treated effluent from the tank is absorbed into the soil.
How often should a septic tank be pumped?
Typically every 3–5 years, depending on tank size and household usage.