Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Plumbing
Septic Tank Sizing Calculator
Estimates the minimum septic tank volume (in gallons) needed for a home based on bedroom count, occupants, plumbing fixtures, and daily wastewater generation. Use it when designing or permitting a new septic system.
Fill in the required fields to see your result.
Plumbing
Water Heater Sizing Calculator
Determines the minimum tank capacity (in gallons) your household needs based on occupants, bedrooms, bathrooms, usage pattern, and heater efficiency. Use it before buying or replacing a water heater.
Fill in the required fields to see your result.
Key differences
| Septic Tank Sizing Calculator | Water Heater Sizing Calculator | |
|---|---|---|
| Category | Plumbing | Plumbing |
| Inputs required | 4 | 5 |
| Result | Minimum Tank Size (gallons) | Recommended Tank Size (gallons) |
| What it does | Estimates the minimum septic tank volume (in gallons) needed for a home based on bedroom count, occupants, plumbing fixtures, and daily wastewater generation. Use it when designing or permitting a new septic system. | Determines the minimum tank capacity (in gallons) your household needs based on occupants, bedrooms, bathrooms, usage pattern, and heater efficiency. Use it before buying or replacing a water heater. |