Is an engine block heater expensive to run?

A timer that starts it 2–3 hours before you leave warms the engine just as well for a third of the cost. At typical use it adds about $16.04 to a monthly electric bill at the US-average rate, but that swings from $11.20 in the cheapest states to $41.72 in the most expensive.

How many watts does an engine block heater use?

Engine Block Heater typically draws about 800 running watts. It's a resistive load, so its startup and running wattage are the same. Check the nameplate or label on your specific unit for its exact rating.

How much electricity (kWh) does an engine block heater use?

At typical use (800 W for 4 hours a day), an engine block heater uses about 3.2 kWh per day — roughly 97 kWh per month, or about 11% of what the average US home uses in a month (863 kWh). Energy used doesn't depend on your electricity rate — only the bill does.

How can I lower the cost of running an engine block heater?

A timer that starts it 2–3 hours before you leave warms the engine just as well for a third of the cost. You can also cut the cost by lowering your electricity rate — many utilities offer cheaper off-peak hours — or simply by running it fewer hours. The calculator on this page shows how changing hours per day or your electricity rate moves the number.

How Much Does It Cost to Run an Engine Block Heater?

A block heater draws about 800 watts — left plugged in all night, every night, it becomes a real winter line item. At the US-average rate of 16.5¢/kWh, running an engine block heater costs about $16.04/month ($192.49/year) at typical use. Adjust the watts, hours, and your rate below for your exact number.

Power (watts)

Hours per day: 4

Days per week: 7

Your state (sets the rate)

Electricity rate ($/kWh)

Cost to run an engine block heater

$192/yr

Per day: $0.53
Per month: $16.04
Energy per year: 1,168 kWh

Cost = power (kW) × hours × days × your rate. Defaults are typical values — enter your appliance's actual watts (often on a label) and your real rate for a precise figure.

How much electricity does an engine block heater use?

At 800 W for 4 hours a day, an engine block heater uses about 3.2 kWh per day — roughly 97 kWh per month and 1,168 kWh per year. That's about 11% of the 863 kWh the average US home uses in a month. Energy use is the same everywhere — only the price per kWh changes your bill.

Wondering about the circuit instead? See how many amps an engine block heater draws.

Cost to run an engine block heater by electricity rate

Same 800 W appliance, 4 h/day — the bill changes with where you live.

Scenario	Rate	Per month	Per year
Cheapest states (North Dakota)	11.5¢	$11.20	$134.44
US average	16.5¢	$16.04	$192.49
Most expensive (Hawaii)	42.9¢	$41.72	$500.60

Find your state's rate on the electricity rates by state page, or see the appliance wattage chart for more devices.

Frequently asked questions

At the US-average residential rate of 16.5¢/kWh, an engine block heater drawing 800 watts for about 4 hours a day costs roughly $0.53 per day, $16.04 per month, and $192.49 per year. Your actual cost depends on your electricity rate and how much you use it, and the calculator on this page adjusts for both.

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How Much Does It Cost to Run an Engine Block Heater?

How much electricity does an engine block heater use?

Cost to run an engine block heater by electricity rate

Frequently asked questions