Electric Water Heater Cost to Run: Per Hour, Month, Year

An average U.S. home that heats water with electricity used 2,706 kWh a year for it in 2020, according to the Energy Information Administration (EIA). At the U.S. average residential price of 18.16 cents per kWh for August 2026, that costs about $491 a year, or about $41 a month. Your cost depends on how much hot water your household uses, the season, your thermostat setting and your electric rate.

Water heating is one of the larger electric loads in a home that has an electric tank, and unlike a space heater it runs all year. This guide shows the math per hour, month and year, what changes it, and when a heat pump water heater or solar makes sense. For your own electric rate, see our electricity rates by state page.

The Formula

Cost = kWh used × your price per kWh

You pay for kilowatt-hours (kWh). A water heater’s element draws its rated power only while it is heating; the thermostat switches it off when the tank reaches its setting. Our kW vs kWh explainer covers the difference between the element’s power (kW) and the energy you are billed for (kWh).

Per hour of heating. A 50-gallon electric tank we checked, A.O. Smith’s E6-50H45DV, has “two 4,500-watt copper heating elements” and a listed maximum wattage of 4,500. At 4,500 watts, the heater uses 4.5 kWh for each hour it is heating:

• At 18.16 cents per kWh: 4.5 × $0.1816 = about 82 cents an hour of heating

That is not a daily cost. How many hours the element runs depends on how much hot water you draw.

What an Average Home Pays

EIA’s Residential Energy Consumption Survey measured average electricity use for water heating at 2,706 kWh a year in 2020 for households that heat water with electricity. That is about 7.4 kWh a day.

Assumption: U.S. average residential price of 18.16 cents per kWh for August 2026 (EIA Electric Power Monthly, released Oct. 23, 2026).

The 2020 usage figure is the latest EIA survey of how much electricity homes use by end use; the price is current. Your own usage may differ a lot from the average.

By Electric Rate

Same 2,706 kWh a year, at different state average prices for August 2026 (EIA):

Use the price per kWh from your own bill, including delivery charges, for the closest estimate. If you are on a time-of-use rate, the hours the tank heats matter too; see our guide to time-of-use rates and solar.

What Makes It Cost More

Household size. More people means more showers, laundry and dishes. ENERGY STAR’s savings table for heat pump water heaters doubles from 1,880 kWh a year for a household of two to 3,760 kWh for a household of four, which reflects how hot-water energy grows with the number of people.

Season. EIA’s monthly averages run from 255 kWh in January to 191 kWh in September, so January use is about a third higher than September’s. Colder incoming water needs more heating to reach the same temperature.

Thermostat setting. The Department of Energy (DOE) says most households “usually only require them to be set at 120ºF” and that a 140ºF setting can waste “$36 to $61 annually in standby heat losses,” the heat a tank loses to the room around it. DOE’s estimate of energy savings from lowering the setting is 4% to 22% a year.

The manufacturer’s estimate for one model. A.O. Smith’s product page shows an estimated energy cost of $573 a year for the 50-gallon model above, based on a home in Nolensville, Tennessee, and a default of 64.3 gallons of hot water a day. That is a high-use assumption, and the estimate depends on local rates; it shows how heavy use pushes costs above the national average.

Heat Pump Water Heaters

A heat pump water heater moves heat from the surrounding air into the water instead of making all of it with a resistance element. ENERGY STAR estimates these savings compared with a standard electric water heater:

ENERGY STAR’s dollar figures use a price of about 14.6 cents per kWh; the last column is our arithmetic at the August 2026 U.S. average. ENERGY STAR also assumes $1,503 of extra upfront cost and a 13-year life. Our heat pump water heater savings guide covers installation needs, payback and rebates.

Water Heating and Solar

If you are sizing a solar system, an electric water heater is a meaningful share of what the panels need to cover. By our math, 2,706 kWh a year is roughly the yearly output of 2 kW of panels, at the U.S. mean output of about 1,375 kWh per kW of panels used in our solar system size calculator. Switching to a heat pump water heater before you size a system can mean fewer panels.

Timing can matter too. Under net metering with full retail credit, it makes little difference when the tank heats. Where exports earn less than the retail rate, or under time-of-use pricing, heating water during sunny hours uses more of your own solar output. Some heat pump water heaters and add-on timers can schedule heating; check what your model supports.

How to Cut the Cost

• Check the setting. DOE says 120°F is enough for most households.
• Fix leaks and use less hot water. Every gallon you do not heat is energy you do not pay for.
• Compare a heat pump water heater when your tank needs replacing, using ENERGY STAR’s estimates and your own rate.
• Look at your bill’s kWh in winter versus fall; a big jump in an all-electric home can point to water heating as well as space heating. Our guide to high electric bills lists other causes.

Sources and verification

Limitations

EIA’s 2,706 kWh is a 2020 national average across homes that heat water with electricity, whatever type of electric water heater they have, so a standard tank in a large household can use more. Prices are August 2026 averages; your rate, including delivery charges, will differ. We did not measure any water heater ourselves.