Electric Water Heater Running Cost
See exactly what your electric water heater costs per day, month and year at US electricity rates.
A standard electric water heater costs roughly $1.80/day, $55/month and $658/year for a household drawing 55 gallons of hot water a day — DOE’s medium-use draw pattern — at the US average electricity rate of 18.44¢/kWh. That is about 3,570 kWh a year.
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Electric Water Heater Monthly Cost by Electricity Rate
| Electricity Rate | 1–2 People (38 gal/day) | 3–4 People (55 gal/day) | 5+ People (84 gal/day) |
|---|---|---|---|
| Idaho — 12.35¢/kWh | ~$25/mo | ~$37/mo | ~$56/mo |
| US average — 18.44¢/kWh | ~$38/mo | ~$55/mo | ~$84/mo |
| California — 33.25¢/kWh | ~$68/mo | ~$99/mo | ~$151/mo |
| Hawaii — 52.00¢/kWh | ~$107/mo | ~$155/mo | ~$236/mo |
Rows are electricity rates, not tank sizes — running cost is set by how much hot water you draw and what you pay per kWh, not by the size of the tank. Volumes are the DOE UEF draw patterns (38 / 55 / 84 gal/day) heated from 58°F to 125°F at UEF 0.92. Monthly figures are annual cost divided by 12. Rates: EIA Electric Power Monthly, Table 5.6.A, May 2026 — a single month, not a 2026 annual average.
What Affects Electric Water Heater Running Cost?
Two things set the bill: how much hot water you actually draw, and what you pay per kWh. A household on DOE’s medium draw pattern of 55 gallons a day uses about 3,570 kWh a year for water heating — about $55/month at the US average of 18.44¢/kWh, but about $89/month at 29.93¢ (New York) and about $37/month at 12.35¢ (Idaho). Check your utility bill and use the calculator above for your own figure.
Tank size has less impact than most people expect. A larger tank holds more hot water at once, but it does not use more energy unless you actually draw more. That is why the table below varies by electricity rate rather than by tank size — the tank you choose should be sized to your peak demand, not to your budget.
Age and insulation matter too. An older tank loses more heat while it stands idle, which is exactly what the UEF rating measures — a standard electric tank rates around 0.92, so roughly 8% of the electricity you buy is lost before anyone opens a tap. DOE puts the standby-loss reduction from adding an insulating blanket to an older, uninsulated tank at 25–45%. See how costs compare in our water heater cost calculator or explore the heat pump water heater cost guide to see the savings available from upgrading.
Electric Water Heater Cost — FAQs
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