Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Water Usage
Rainwater Harvesting Calculator
Estimate how many gallons of rainwater your roof can collect annually and what tank size you need to meet your water goals. Useful for sizing cisterns, rain barrels, and off-grid water systems.
Fill in the required fields to see your result.
Water Usage
Household Water Bill Estimator
Estimate your monthly residential water bill from household size, an assumed per-person usage level, and the local volumetric water rate. A quick budgeting tool, not a substitute for reading your utility statement.
Fill in the required fields to see your result.
Key differences
| Rainwater Harvesting Calculator | Household Water Bill Estimator | |
|---|---|---|
| Category | Water Usage | Water Usage |
| Inputs required | 4 | 3 |
| Result | Annual Rainwater Collection (gallons) | Monthly Water Bill ($) |
| What it does | Estimate how many gallons of rainwater your roof can collect annually and what tank size you need to meet your water goals. Useful for sizing cisterns, rain barrels, and off-grid water systems. | Estimate your monthly residential water bill from household size, an assumed per-person usage level, and the local volumetric water rate. A quick budgeting tool, not a substitute for reading your utility statement. |