Is an attic fan expensive to run?

Seal attic-floor air leaks first — otherwise the fan can pull conditioned air up out of the house. At typical use it adds about $9.02 to a monthly electric bill at the US-average rate, but that swings from $6.30 in the cheapest states to $23.47 in the most expensive.

How many watts does an attic fan use?

Attic Fan typically draws about 300 running watts. Because it has a motor or compressor, it briefly spikes to around 700 watts at startup, which matters for generator and breaker sizing but not for energy cost. Check the nameplate or label on your specific unit for its exact rating.

How much electricity (kWh) does an attic fan use?

At typical use (300 W for 6 hours a day), an attic fan uses about 1.8 kWh per day — roughly 55 kWh per month, or about 6% 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 attic fan?

Seal attic-floor air leaks first — otherwise the fan can pull conditioned air up out of the house. 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 Attic Fan?

An attic fan knocks down attic temperatures for a few hundred watts, easing the load on AC below. At the US-average rate of 16.5¢/kWh, running an attic fan costs about $9.02/month ($108.27/year) at typical use. Adjust the watts, hours, and your rate below for your exact number.

Power (watts)

Hours per day: 6

Days per week: 7

Your state (sets the rate)

Electricity rate ($/kWh)

Cost to run an attic fan

$108/yr

Per day: $0.30
Per month: $9.02
Energy per year: 657 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 attic fan use?

At 300 W for 6 hours a day, an attic fan uses about 1.8 kWh per day — roughly 55 kWh per month and 657 kWh per year. That's about 6% 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 attic fan draws.

Cost to run an attic fan by electricity rate

Same 300 W appliance, 6 h/day — the bill changes with where you live.

Scenario	Rate	Per month	Per year
Cheapest states (North Dakota)	11.5¢	$6.30	$75.62
US average	16.5¢	$9.02	$108.27
Most expensive (Hawaii)	42.9¢	$23.47	$281.59

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 attic fan drawing 300 watts for about 6 hours a day costs roughly $0.30 per day, $9.02 per month, and $108.27 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 Attic Fan?

How much electricity does an attic fan use?

Cost to run an attic fan by electricity rate

Frequently asked questions