See what switching to a heat pump water heater (HPWH) could save you each year compared with your current water heater — based on your household, your energy rates, and standard engineering assumptions.
Your home
Advanced assumptions
Your estimate
Updated liveEstimates only. Actual savings depend on your climate, usage patterns, installation details, and rate plan. Verify your electricity and gas rates with your utility before making a decision.
Methodology and assumptions
This calculator estimates the energy needed to heat your household’s hot water, then divides by each heater’s efficiency to find purchased energy and cost. The 10-year figure is gross energy-bill savings before installation cost; it does not subtract the purchase price.
- Heat required: gallons/day × temperature rise (°F) × 8.34 BTU per gallon per °F, × 365 days.
- Defaults: incoming water 55°F, setpoint 120°F (65°F rise).
- Conversions: 1 kWh = 3,412 BTU; 1 therm = 100,000 BTU.
- No federal tax credit is included: the 25C home-improvement credit ended December 31, 2025, so 2026 installations assume no federal credit.
- Payback is simple installed cost ÷ annual savings, ignoring future rate changes, maintenance differences, and the time value of money.
- CO2: electricity uses the US average of about 0.85 lb CO2 per kWh; natural gas uses about 11.7 lb CO2 per therm (EPA). Your grid mix varies — it can be much cleaner or dirtier depending on your state and utility.
| Heater type | UEF used |
|---|---|
| Electric resistance tank | 0.95 |
| Natural gas tank | 0.65 |
| Older heat pump water heater | 2.2 (editable above) |
| New heat pump water heater | 3.5 (editable above) |
Household-size presets map to roughly 30 / 50 / 64 / 76 / 90 gallons per day for 1 / 2 / 3 / 4 / 5+ people, based on typical US residential hot-water use.