How Much Does It Cost to Run an Electric Water Heater?
$75.17
Running a 4,500 W electric water heater for 3 hours a day uses about 405 kWh a month, which costs about $75.17 at the U.S. average rate of 18.56¢ per kWh, or about $0.84 per hour of use.
Monthly cost of a 4,500 W electric water heater at different electricity rates
| Electricity rate | Per month | Per hour |
|---|---|---|
| 12¢/kWh | $48.60 | $0.54 |
| 15¢/kWh | $60.75 | $0.67 |
| 18.56¢/kWh | $75.17 | $0.84 |
| 22¢/kWh | $89.10 | $0.99 |
| 28¢/kWh | $113 | $1.26 |
| 35¢/kWh | $142 | $1.58 |
Adjust the numbers
The calculator below is pre-filled with the numbers above. Change any value to match your project.
- Cost per day
- $2.51
- Cost per year
- $915 (used every day)
- Cost per hour
- $0.84
- Energy per month
- 405 kWh
What you will need
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How it is calculated
Energy use in kilowatt-hours is watts × hours ÷ 1,000. Multiply by your price per kWh to get the cost, as described in Virginia Cooperative Extension’s guide Estimating Appliance and Home Electronic Energy Use.
The default rate is the U.S. average residential price of 18.56¢ per kWh from the EIA Electric Power Monthly (March 2026). Use the rate on your own bill for a more accurate result.
Open the full electricity cost calculator for other shapes, a worked example and FAQs.