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Electricity cost guide

Electric Tank Water Heater Cost Calculator

A conventional electric water heater is a major load because it heats stored water and replaces heat lost through the tank.

4,500 W starting input 3 hr/day No sign-up

Typical starting estimate

$74.68/month405.0 kWh at 18.44¢/kWh

Your inputs

Calculate operating cost

watts
hours
days
$/kWh
EIA residential average price, not a utility-specific rate. Your bill’s all-in rate gives the best personal estimate.

Live estimate

Estimated monthly cost$74.68at 18.44¢ per kWh
Per day$2.49
Per year$909
Monthly use405.0 kWh
Transparent calculation(4500 W ÷ 1,000) × 3 hr × 30 days × $0.184/kWh

Actual use can differ when equipment cycles or changes power. Measure at the wall when precision matters.

How the electric water heater estimate works

The calculator converts watts to kilowatts, multiplies by effective runtime, and then applies the electricity price. With the starting inputs, this electric water heater uses about 405.0 kWh per month.

4,500 W ÷ 1,000 × 3 hours × 30 days × $0.1844/kWh = $74.68

Household hot-water demand, setpoint, tank insulation, inlet temperature, and leaks determine element runtime.

How runtime changes the estimate

Daily runtimeMonthly useMonthly cost
1 hour/day135.0 kWh$24.89
4 hours/day540.0 kWh$99.58
8 hours/day1080.0 kWh$199.15

These scenarios assume the device draws the full starting wattage for the entire runtime. Cycling and variable-speed equipment should use effective runtime or measured kWh.

Estimated monthly cost in high-price states

State2026-05 average priceEstimated cost
Hawaii52.00¢/kWh$210.60/mo
California33.25¢/kWh$134.66/mo
New York29.93¢/kWh$121.22/mo
Rhode Island29.46¢/kWh$119.31/mo

Practical ways to reduce cost

  • Repair hot-water leaks.
  • Use an appropriate safe temperature setting.
  • Insulate accessible hot-water pipes.

Compare related equipment

Tankless Electric Water Heater405.0 kWh/mo →Heat Pump Water Heater144.0 kWh/mo →

Frequently asked questions

How much electricity does a electric water heater use?

Using a 4,500-watt starting input for 3 hours per day and 30 days per month produces an estimate of 405.0 kWh per month. Actual use can differ because equipment may cycle or change power.

How much does it cost to run a electric water heater each month?

At the latest 2026-05 U.S. residential average price of 18.44 cents per kWh, the starting estimate is $74.68 per month. Replace the inputs with your own numbers for a personal estimate.

What number should I use for the electricity price?

Divide the total electric charges on your latest bill by the total kWh used for an all-in price. State averages are useful for comparison but are not utility-specific rates.

Data source

U.S. Energy Information Administration, Electricity Retail Sales, residential average price. Latest monthly data: 2026-05; comparison baseline: 2025 annual. Verified 2026-08-05. Monthly prices can vary seasonally and are not utility-specific rates.

View EIA data