Electricity use guide
How much does an electric storage water heater cost to run?
Using a planning draw of 4,500 watts for 3 hours a day, this example uses 13.50 kWh daily. At the June 2026 monthly average U.S. residential rate of $0.1834 per kWh, that is about $2.48 per day or $903.70 per year.
- Daily electricity
- 13.50 kWh
- Monthly cost
- $75.31
- Annual electricity
- 4927.5 kWh
- Annual cost
- $903.70
Calculation for this example
4,500 W ÷ 1,000 × 3 hr/day × 365 days × $0.1834/kWh = $903.70/yearElectricity use in kilowatt-hours equals watts divided by 1,000, multiplied by runtime. Cost equals that energy use multiplied by the price per kWh.
What changes the actual cost?
- Thermostat settings, room or tank temperature, climate, insulation, and equipment condition change how often the unit cycles.
- Use equivalent full-power hours rather than total plugged-in hours when the compressor or heating element switches on and off.
The example is a labeled planning estimate, not a specification for every model. Its national average rate includes fixed-charge and tax revenue; no separate fees are added. It is not the exact additional charge for using this appliance on your tariff.
Hourly, daily, and annual running costs
These fixed examples use residential electricity prices from the June 2026 monthly average, not your selected calculator rate. All longer periods assume the example schedule every day; seasonal equipment will differ. Values below one cent display as <$0.01.
| Period | Energy kWh | Cost $0.1834/kWh |
|---|---|---|
| One hour at stated power | 4.500 | $0.83 |
| Day at example schedule | 13.500 | $2.48 |
| Week (7 days) | 94.500 | $17.33 |
| Average month (365 ÷ 12 days) | 410.625 | $75.31 |
| Year (365 days) | 4927.500 | $903.70 |
Compare state-average rates Virginia, Washington, California, and Hawaii
Scroll sideways to compare all rates. With the table focused, use Left and Right arrow keys.
| Period | Energy kWh | U.S. average $0.1834/kWh | Virginia $0.1722/kWh | Washington $0.1491/kWh | California $0.3474/kWh | Hawaii $0.5272/kWh |
|---|---|---|---|---|---|---|
| One hour at stated power | 4.500 | $0.83 | $0.77 | $0.67 | $1.56 | $2.37 |
| Day at example schedule | 13.500 | $2.48 | $2.32 | $2.01 | $4.69 | $7.12 |
| Week (7 days) | 94.500 | $17.33 | $16.27 | $14.09 | $32.83 | $49.82 |
| Average month (365 ÷ 12 days) | 410.625 | $75.31 | $70.71 | $61.22 | $142.65 | $216.48 |
| Year (365 days) | 4927.500 | $903.70 | $848.52 | $734.69 | $1711.81 | $2597.78 |
Source: U.S. EIA residential electricity prices. These averages include fixed-charge and tax revenue, so they are not your utility’s marginal price for an additional kWh.
A heating-element rating is not a daily energy total
The example is for a resistance-heated electric storage tank. Heat-pump water heaters are a different technology. ENERGY STAR notes that their installation environment affects performance and that backup resistance heating can increase use under some conditions.
ENERGY STAR: heat-pump water heaters supports the operating guidance; the wattages and schedules here are illustrative inputs, not measurements supplied by that source.
A worked example you can adapt
A 4.5 kW element operating for two equivalent active hours uses 9 kWh, costing $1.80 at $0.20/kWh. Do not multiply that element rating by all 24 hours unless it actually operates continuously. Hot-water demand and standby heat loss both affect daily energy.
Ways to make your estimate more useful
- Use energy figures for your exact model and operating mode.
- Separate a resistance-tank example from a hybrid heat-pump model.
- For hardwired equipment, use suitable whole-circuit monitoring or a qualified professional, not an ordinary plug-in meter.
A common question
Can I compare replacements using the heating-element wattage?
Not reliably. A larger element may heat for a shorter time, and a heat pump moves heat rather than relying only on resistance elements. Compare annual energy for similar hot-water demand and account for installation costs separately.
Get a result for your appliance
Enter the wattage from your appliance label, your typical schedule, and the electricity rate from your bill. The calculator shows daily and annual energy, cost, source details, and the arithmetic used.
Calculate your electric storage water heater cost