Water heating is usually the second largest line on a household electricity bill, behind heating and cooling and ahead of everything else. It is also the one people never think about, because the appliance sits in a closet doing its job silently and there is no thermostat on the wall to fiddle with.
A standard electric tank water heater uses a 4,500 W element that runs roughly three hours a day for an average household. That is about $2.21 a day at 18.44ยข per kWh, $66.38 a month, and $808 a year. Households with teenagers, long showers or a dishwasher running nightly will be well above that.
Calculate it for your own electric water heater
Change any box. The result updates as you type.
Planning estimate. The rate box is prefilled with a regional average; the figure on your own bill is the one that matters. Power is draw while running, not while switched on.
| Run time | Electricity used | Cost |
|---|---|---|
| Per hour of runtime | 4.00 kWh | $0.74 |
| Per day at 3 hours | 12.00 kWh | $2.21 |
| Per week | 84.00 kWh | $15.49 |
| Per 30-day month | 360.00 kWh | $66.38 |
| Per year of that pattern | 4,380.00 kWh | $808 |
Two elements, one at a time
Tank heaters have two elements, upper and lower, and they do not run at the same time. The control alternates between them, so a heater with two 4,500 W elements still only draws 4,500 W. The element runs whenever the tank temperature drops below setpoint, which happens when you draw hot water and, more slowly, as the tank loses heat to the room through its insulation.
That second part is standby loss, and on an older tank it can be a fifth of the total. A tank installed in an unheated garage or crawlspace loses noticeably more than the same tank in a conditioned utility room.
| Rated power | Per hour | Per day (3 h) | Per month |
|---|---|---|---|
| 3,000 W | $0.55 | $1.66 | $49.79 |
| 3,800 W | $0.70 | $2.10 | $63.06 |
| 4,500 W | $0.83 | $2.49 | $74.68 |
| 5,000 W | $0.92 | $2.77 | $82.98 |
| 5,500 W | $1.01 | $3.04 | $91.28 |
What each shower actually costs
Element runtime tracks hot water use almost linearly. Rough figures per event, at 4,500 W:
- A ten-minute shower reheats roughly 17 gallons, which is about 25 minutes of element time, or $0.31.
- A dishwasher cycle drawing hot water costs roughly a third of that on top of the dishwasher own element.
- A hot-water clothes wash is the most expensive laundry setting by a wide margin, which is why cold-water detergent exists.
Multiply by the number of people in the house and the picture assembles itself quickly.
| Hours per day | kWh per day | Per day | Per 30 days |
|---|---|---|---|
| 1 h | 4.00 | $0.74 | $22.13 |
| 2 h | 8.00 | $1.48 | $44.26 |
| 3 h | 12.00 | $2.21 | $66.38 |
| 4 h | 16.00 | $2.95 | $88.51 |
| 5 h | 20.00 | $3.69 | $111 |
| 6 h | 24.00 | $4.43 | $133 |
Water heater cost across electricity rates
Three hours of element time a day, every common rate.
| Your rate | Per hour | Per day (3 h) | Per month | Per year |
|---|---|---|---|---|
| 10.00¢/kWh | $0.40 | $1.20 | $36.00 | $438 |
| 13.00¢/kWh | $0.52 | $1.56 | $46.80 | $569 |
| 15.00¢/kWh | $0.60 | $1.80 | $54.00 | $657 |
| 18.44¢/kWh | $0.74 | $2.21 | $66.38 | $808 |
| 22.00¢/kWh | $0.88 | $2.64 | $79.20 | $964 |
| 26.00¢/kWh | $1.04 | $3.12 | $93.60 | $1,139 |
| 30.00¢/kWh | $1.20 | $3.60 | $108 | $1,314 |
| 35.00¢/kWh | $1.40 | $4.20 | $126 | $1,533 |
Water heater running cost by state
Same tank, same household, different tariff.
| State | Rate | Per hour | Per day | Per month |
|---|---|---|---|---|
| Alabama | 16.77¢ | $0.67 | $2.01 | $60.37 |
| Alaska | 28.23¢ | $1.13 | $3.39 | $102 |
| Arizona | 15.23¢ | $0.61 | $1.83 | $54.83 |
| Arkansas | 14.36¢ | $0.57 | $1.72 | $51.70 |
| California | 33.25¢ | $1.33 | $3.99 | $120 |
| Colorado | 16.16¢ | $0.65 | $1.94 | $58.18 |
| Connecticut | 27.37¢ | $1.09 | $3.28 | $98.53 |
| Delaware | 19.38¢ | $0.78 | $2.33 | $69.77 |
| District of Columbia | 25.40¢ | $1.02 | $3.05 | $91.44 |
| Florida | 15.17¢ | $0.61 | $1.82 | $54.61 |
| Georgia | 15.84¢ | $0.63 | $1.90 | $57.02 |
| Hawaii | 52.00¢ | $2.08 | $6.24 | $187 |
| Idaho | 12.35¢ | $0.49 | $1.48 | $44.46 |
| Illinois | 23.85¢ | $0.95 | $2.86 | $85.86 |
| Indiana | 18.15¢ | $0.73 | $2.18 | $65.34 |
| Iowa | 14.14¢ | $0.57 | $1.70 | $50.90 |
| Kansas | 15.13¢ | $0.61 | $1.82 | $54.47 |
| Kentucky | 14.98¢ | $0.60 | $1.80 | $53.93 |
| Louisiana | 14.15¢ | $0.57 | $1.70 | $50.94 |
| Maine | 28.63¢ | $1.15 | $3.44 | $103 |
| Maryland | 21.77¢ | $0.87 | $2.61 | $78.37 |
| Massachusetts | 28.82¢ | $1.15 | $3.46 | $104 |
| Michigan | 22.01¢ | $0.88 | $2.64 | $79.24 |
| Minnesota | 16.95¢ | $0.68 | $2.03 | $61.02 |
| Mississippi | 16.16¢ | $0.65 | $1.94 | $58.18 |
| Missouri | 13.68¢ | $0.55 | $1.64 | $49.25 |
| Montana | 14.67¢ | $0.59 | $1.76 | $52.81 |
| Nebraska | 13.59¢ | $0.54 | $1.63 | $48.92 |
| Nevada | 13.60¢ | $0.54 | $1.63 | $48.96 |
| New Hampshire | 27.33¢ | $1.09 | $3.28 | $98.39 |
| New Jersey | 23.27¢ | $0.93 | $2.79 | $83.77 |
| New Mexico | 14.12¢ | $0.56 | $1.69 | $50.83 |
| New York | 29.93¢ | $1.20 | $3.59 | $108 |
| North Carolina | 15.09¢ | $0.60 | $1.81 | $54.32 |
| North Dakota | 13.61¢ | $0.54 | $1.63 | $49.00 |
| Ohio | 19.52¢ | $0.78 | $2.34 | $70.27 |
| Oklahoma | 13.38¢ | $0.54 | $1.61 | $48.17 |
| Oregon | 16.27¢ | $0.65 | $1.95 | $58.57 |
| Pennsylvania | 21.55¢ | $0.86 | $2.59 | $77.58 |
| Rhode Island | 29.46¢ | $1.18 | $3.54 | $106 |
| South Carolina | 16.18¢ | $0.65 | $1.94 | $58.25 |
| South Dakota | 15.73¢ | $0.63 | $1.89 | $56.63 |
| Tennessee | 14.47¢ | $0.58 | $1.74 | $52.09 |
| Texas | 16.44¢ | $0.66 | $1.97 | $59.18 |
| Utah | 12.96¢ | $0.52 | $1.56 | $46.66 |
| Vermont | 24.89¢ | $1.00 | $2.99 | $89.60 |
| Virginia | 17.61¢ | $0.70 | $2.11 | $63.40 |
| Washington | 14.95¢ | $0.60 | $1.79 | $53.82 |
| West Virginia | 16.80¢ | $0.67 | $2.02 | $60.48 |
| Wisconsin | 19.74¢ | $0.79 | $2.37 | $71.06 |
| Wyoming | 14.80¢ | $0.59 | $1.78 | $53.28 |
Six changes worth making
- Set the thermostat to 120 degrees. Many are shipped at 140. Every 10 degrees of setpoint reduction cuts standby loss by around 4 percent, and 120 is the temperature health authorities recommend anyway. Below 120 you start risking bacterial growth in the tank, so 120 is the floor, not a starting point for further cuts.
- Insulate the first six feet of hot and cold pipe. Pipe sleeve is inexpensive and reduces the heat that walks out of the tank through the plumbing.
- Add a tank blanket if the tank is warm to the touch. Modern tanks are well insulated and gain little; a pre-2005 tank often gains a lot. Do not cover the top of a gas unit.
- Fix dripping hot taps. A hot tap dripping once a second is heating water that goes straight down the drain.
- Flush sediment annually. Sediment insulates the lower element from the water, so it runs longer to achieve the same result.
- Put it on a timer only if you have a predictable schedule. Timers save standby loss but a tank that has cooled fully takes real energy to bring back. The savings are modest and the complaints about cold showers are not.
The heat pump water heater question
A heat pump water heater does the same job by moving heat from the surrounding air into the tank rather than making heat with an element. It uses roughly a third of the electricity for the same hot water, which turns a $808 annual cost into something closer to $101.
The catches are real. They cost more up front, they need roughly 700 to 1,000 cubic feet of space around them to draw heat from, they cool and dehumidify the room they sit in, and they are audible. In a garage in a warm climate they are close to a free win. In a small utility closet in a cold basement they are a poor fit. Our heat pump water heater savings calculator runs the comparison with your own numbers.
How this compares to everything else you plug in
Per hour of element time against the other large loads in the house.
| Appliance | Typical power | Cost per hour |
|---|---|---|
| Electric water heater | 4,000 W | $0.74 |
| Heat pump water heater | 500 W | $0.09 |
| Electric clothes dryer | 3,000 W | $0.55 |
| Dishwasher | 1,800 W | $0.33 |
| Electric oven | 2,400 W | $0.44 |
| Washing machine | 500 W | $0.09 |
Questions people actually ask
How much does it cost to run an electric water heater per month?
How many watts does a water heater use?
Is it cheaper to turn the water heater off when away?
What temperature should an electric water heater be set to?
Does a tankless electric water heater cost less to run?
Why did my electricity bill jump with no change in habits?
Related running costs
Running it on solar
A electric water heater uses 12.00 kWh a day, which needs about 9 standard 400 W panels. Full array, battery and inverter sizing is on how many solar panels to run a electric water heater.
Run the numbers on your own bill
- Heat Pump Water Heater Savings Calculator
- Water Heater Size and First-Hour Rating Calculator
- Electricity Cost Calculator
Costs on this page use a national average residential rate of 18.44¢ per kWh (August 2026, EIA-derived state residential averages). Your own rate is printed on your electricity bill and is the number that actually matters. Every figure here is recalculated from one central rate setting, so these tables move when the national average moves.