How much does an electric water heater cost per month in Hawaii?

About $140 a month, assuming 3,500 kWh a year at 48.00¢/kWh.

How many kilowatt-hours does an electric water heater use?

Roughly 3,500 kWh a year under these assumptions.

Is that expensive compared with other states?

Hawaii has the most expensive average residential rate in the country, so this appliance costs more here than the U.S. average of $641 a year.

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Cost to run an electric water heater in Hawaii (July 2026 rates)

At 48.00¢ per kilowatt-hour — Hawaii's average residential price in July 2026 — running an electric water heater costs $1,680 a year. That is 162% more than the national average of $641. Hawaii's residential rate is up 22.0% from July 2025, which moves this appliance from $1,378 to $1,680 a year.

Per day: $4.60
Per month: $140
Per year: $1,680

Assumption: 3,500 kWh a year. A 50-gallon resistance tank for a household of three or four. This is typically the largest or second-largest electric load in a home without electric heat. Use the calculator to swap in the numbers from your own model.

Related calculators: work out whether a heat-pump water heater pays back.

How Hawaii compares

Hawaii pays 48.00¢/kWh, the most expensive residential electricity of the 51 U.S. jurisdictions EIA reports. For this appliance that works out to $1,039 more a year than the typical U.S. household pays for the same use. Running the same electric water heater costs $445 a year in Louisiana and $1,680 in Hawaii, so where you live changes this bill by $1,235 a year.

State	Rate	Per month	Per year
New York	29.90¢	$87.21	$1,046
Massachusetts	30.49¢	$88.93	$1,067
Maine	32.41¢	$94.53	$1,134
California	33.61¢	$98.03	$1,176
Hawaii	48.00¢	$140	$1,680

States ranked by average residential price, cheapest first. See all 51 states for an electric water heater.

What else costs about the same in Hawaii

Electric car$1,824 a year in HI Hot tub$1,200 a year in HI Central air conditioner$1,129 a year in HI

Cutting the number down

A heat-pump water heater does the same job for roughly a third of the electricity, which is why it usually pays back faster than any other upgrade in the house.
Dropping the setpoint from 140 F to 120 F cuts standby losses and scalding risk at once.
An insulating blanket on an older tank pays for itself in a season; check the manufacturer's guidance first.

Questions

How much does an electric water heater cost per month in Hawaii?: About $140 a month, assuming 3,500 kWh a year at 48.00¢/kWh.
How many kilowatt-hours does an electric water heater use?: Roughly 3,500 kWh a year under these assumptions.
Is that expensive compared with other states?: Hawaii has the most expensive average residential rate in the country, so this appliance costs more here than the U.S. average of $641 a year.