Electric Water Heater cost calculator
Find it on the label.
Use the price from your bill if you know it.
Cost to run this device
Cost = watts divided by 1,000, times hours, times your price per kWh. It covers energy only, not the cost of buying the device.
Typical draw
4,500 W
Range 3,000 to 5,500 W
Hours a day
2.5
Assumed day of use
Energy a month
342 kWh
11.3 kWh a day
Cost a month
$59
At 17.23 cents per kWh
What an electric water heater costs to run
| Period | Energy | Cost |
|---|---|---|
| One hour of running | 4.50 kWh | $0.78 |
| One day (2.5 hours) | 11.25 kWh | $1.94 |
| One month (30.4 days) | 342 kWh | $59 |
| One year (12 months) | 4,104 kWh | $707 |
Source: Planning watts of 4,500 and 2.5 hours a day, hours of element running time a day. Price: 17.23 cents per kWh, the 2025 US residential average from EIA Form EIA-861.
The monthly cost is 39% of the $150.68 average US electric bill. It runs all year, so the yearly cost is twelve times the monthly figure.
Three real-life cases
One figure cannot fit every home. These three cases show how much the answer moves with the equipment and the hours.
| Case | Watts | Hours a day | kWh a month | Cost a month |
|---|---|---|---|---|
| One or two people | 4,500 | 1.5 | 205 | $35 |
| Family of four | 4,500 | 2.5 | 342 | $59 |
| Large family, high use | 4,500 | 4 | 547 | $94 |
The lowest case costs $35 a month and the highest $94. Use the calculator above to match your own.
What it costs in other states
The same electric water heater costs different amounts depending on the state, because the price per kWh differs. Here are the three cheapest states, the US average and the three costliest, for the same 342 kWh a month.
| Place | Cents per kWh | Cost a month |
|---|---|---|
| North Dakota | 11.82 | $40 |
| Idaho | 11.83 | $40 |
| Nebraska | 12.05 | $41 |
| United States average | 17.23 | $59 |
| Hawaii | 40.40 | $138 |
| California | 31.35 | $107 |
| Massachusetts | 30.41 | $104 |
Source: U.S. Energy Information Administration, Form EIA-861 (final 2025 data). Price is residential revenue divided by sales and includes fixed charges.
See electricity rates in every state to find your own.
How an electric water heater uses electricity
A tank water heater has two heating elements, but only one runs at a time. The element switches on when the tank cools below its setting and off when it is hot again, so hours of running time depend on how much hot water is used and how well the tank holds heat.
The number of people, hot water habits, incoming water temperature and the thermostat setting set the hours. Water heating is one of the largest electric end uses in homes that heat water with electricity.
For scale, the EIA Residential Energy Consumption Survey found the average US home used about 105 kWh a month on water heating in 2020, and the average detached house about 104 kWh. These averages include homes with no such equipment, so a home that has it uses more.
The range for this kind of appliance runs from about 3,000 to 5,500 watts. At 2.5 hours a day that is $39 to $72 a month, which is why checking the label on yours is worth the minute.
Ways to cut the cost of an electric water heater
- Set the thermostat to 120 degrees Fahrenheit.
- Insulate the tank and the first few feet of hot pipe.
- A heat pump water heater uses much less electricity than a standard electric tank.
Next step: Tankless water heater costs. For general ideas, read how to lower your electric bill.
Other appliances in the water group: Tankless Water Heater, Well Pump, Sump Pump.
How we got these numbers
The cost is watts divided by 1,000, times hours, times your price per kWh. The 4,500 watts is a planning figure for this kind of appliance, set from typical product ratings, and the 2.5 hours is an assumed day of use. Neither is copied from a federal table. Federal guidance describes the method and warns that real wattage varies, so we publish our own typical ranges and label them as such. Prices come from EIA Form EIA-861 for 2025.
The calculation is the standard one used in the U.S. Department of Energy's consumer guidance on estimating appliance energy use. Wattage varies by product age and features, so the label on your own appliance beats any average. Read more in our methodology.
Electric Water Heater cost questions
How much does an electric water heater cost to run per month?
For a family of four, the table on this page gives a typical figure at the US average price. Your bill depends on your price per kWh, how much hot water you use and the cold water temperature in winter.
Does turning the water heater thermostat down save money?
Yes. A lower set point reduces heat loss from the tank and the energy used to heat the water. 120 degrees Fahrenheit is a common recommended setting.
How much does an electric water heater cost to run per hour?
At 4,500 watts and the 2025 US average price of 17.23 cents per kWh, about $0.78 an hour. Use your own price to get your own figure.
How many kWh does an electric water heater use in a month?
About 342 kWh for 2.5 hours of use a day over 30.4 days at 4,500 watts. A different wattage or schedule changes the total in proportion.