Water Heater Cost Calculator
Estimate water heating energy cost from gallons, temperature rise, and efficiency.
This page is an editable estimator with realistic defaults so you can model your own situation in minutes.
kWh = gallons x 8.34 x temperature rise / 3,412 / efficiency.
Treat the result as a planning estimate and verify important numbers with the relevant official source before acting.
| Hot water use | 55 gal/day | |
|---|---|---|
| Temperature rise | 70 F | |
| Efficiency | 90% |
Assumptions
- Heating, cooling, and water heating estimates vary with climate, setpoints, insulation, equipment condition, and usage.
- HVAC equipment sizing should be confirmed with a qualified contractor and proper load calculations.
- Efficiency ratings and real-world performance can differ by temperature and operating conditions.
How this calculator works
Formula used
kWh = gallons x 8.34 x temperature rise / 3,412 / efficiency.
Example calculation
Plug in your own numbers and the result updates instantly. kWh = gallons x 8.34 x temperature rise / 3,412 / efficiency.
Water Heater Cost Calculator FAQ
Is this water heater cost calculator exact?
No. It is an estimate for planning only. Actual bills, savings, and sizing depend on utility tariffs, weather, usage behavior, equipment efficiency, installation quality, local code, and product specifications.
What electricity rate should I enter?
Use your all-in average rate if possible: supply, delivery, taxes, and riders divided by total kWh. Time-of-use plans, demand charges, fixed fees, and tiered rates can change the result.
Should I verify before buying equipment?
Yes. Confirm solar, battery, generator, HVAC, water heater, insulation, window, and electrical decisions with qualified installers, electricians, utility programs, and local permitting requirements.