Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Climate
Rainwater Harvesting Calculator
Estimate how many gallons of rainwater your roof can collect each year and how much you could save on your water bill. Ideal for homeowners planning a rain barrel or cistern system.
Fill in the required fields to see your result.
Climate
Heat Pump Efficiency Calculator
Calculate how many years it will take to recover a heat pump installation cost through energy bill savings compared to your current heating system. Use it before purchasing or when applying for rebates.
Fill in the required fields to see your result.
Key differences
| Rainwater Harvesting Calculator | Heat Pump Efficiency Calculator | |
|---|---|---|
| Category | Climate | Climate |
| Inputs required | 4 | 4 |
| Result | Annual Water Cost Savings ($) | Annual Savings After Payback ($) |
| What it does | Estimate how many gallons of rainwater your roof can collect each year and how much you could save on your water bill. Ideal for homeowners planning a rain barrel or cistern system. | Calculate how many years it will take to recover a heat pump installation cost through energy bill savings compared to your current heating system. Use it before purchasing or when applying for rebates. |