How Much Does It Cost to Run an electric water heater?
A typical electric water heater uses about 4,500 watts, which costs about $0.81 per hour. Used 3 hours a day, that is $2.43 per day, $74 per month and about $887 per year at the US average of about 18 cents per kWh. Change the numbers below for your own model and rate.
Typical estimate: the elements run about 3 hours a day for a family of three or four. These are typical estimates – check your own label or use a plug-in meter for exact figures.
Electric water heater running cost by electricity rate
Rates vary widely across the country. $0.12 is typical of low-cost areas, $0.18 is about the national average, and $0.25–$0.35 or more is common in high-cost areas such as parts of California, New England and Hawaii.
| Rate per kWh | Per hour | Per day | Per month | Per year |
|---|---|---|---|---|
| $0.12 | $0.540 | $1.62 | $49.28 | $591 |
| $0.18 | $0.810 | $2.43 | $73.92 | $887 |
| $0.25 | $1.125 | $3.38 | $102.67 | $1,232 |
| $0.35 | $1.575 | $4.73 | $143.73 | $1,725 |
Based on 4,500 W for 3 h/day; month = 30.42 days.
Cost by hours of use per day
| Hours per day | kWh per month | Per day | Per month | Per year |
|---|---|---|---|---|
| 2 h | 274 | $1.62 | $49.28 | $591 |
| 3 h | 411 | $2.43 | $73.92 | $887 |
| 5 h | 684 | $4.05 | $123.20 | $1,478 |
At 18 cents per kWh and 4,500 W.
Low, typical and high wattage
A standard tank has one or two 4,500 W elements (only one fires at a time in most models). A heat pump water heater uses far less.
| Case | Watts | Per hour | Per month | Per year |
|---|---|---|---|---|
| Low | 3,000 | $0.540 | $49.28 | $591 |
| Typical | 4,500 | $0.810 | $73.92 | $887 |
| High | 5,500 | $0.990 | $90.35 | $1,084 |
At 3 h/day and 18 cents per kWh.
How it is calculated
4,500 W × 3 h ÷ 1,000 = 13.5 kWh per day
13.5 kWh × $0.18 = $2.43 per day
$2.43 × 30.42 days = $73.92 per month
How to cut the cost of running an electric water heater
- Turn the thermostat down to 120°F – DOE says most households only need 120°F, and lowering a 140°F setting cuts standby heat losses (DOE puts those losses at $36–$61 a year at 140°F).
- Add a tank blanket on older tanks in cold garages or basements, and insulate hot-water pipes (DOE estimates pipe insulation saves about 3%–4% of water-heating energy). Do not set the thermostat above 130°F under a blanket.
- DOE says a heat pump water heater can be two to three times as efficient as a standard electric tank, so it can use about a third to half the electricity in a suitable space.
- Set a timer or vacation mode during trips; heating 40–50 gallons that nobody uses still costs standby energy.
Frequently asked questions
How much does it cost to run an electric water heater per month?
At 18 cents per kWh, a typical 4,500 W electric water heater used 3 hours a day costs about $73.92 per month (411 kWh). That is about $887 a year.
How much does it cost to run an electric water heater per hour?
About $0.810 per hour at 18 cents per kWh, or $1.575 per hour if you pay 35 cents per kWh. Multiply by your hours of use to estimate any day.
Why does the cost of an electric water heater vary so much?
Wattage varies by model and setting – from 3,000 W to 5,500 W here. At the same 3 hours a day and 18 cents per kWh, that is $49 to $90 per month. Your electricity rate matters just as much: at 35 cents per kWh the typical unit costs $144 per month.