Attic fan: electricity cost calculator
Quick answer: a typical attic fan costs about $10/month while in use at the U.S. average electricity price (18.44¢/kWh) across a 5-month season (about $51/year). Your number depends on wattage, runtime and your state — calculate it below.
Powered attic ventilators draw 100–500 W and run on a thermostat during hot afternoons. Solar-powered models cost nothing to run; wired models cost a few dollars a month in season.
1.80 kWh/day used · 55 kWh/month in use · 274 kWh/year at 18.44¢ per kWh (5 months of use per year)
Low, typical and heavy use
Monthly cost while in use, at the U.S. average price of 18.44¢/kWh.
| Scenario | Watts | Hours/day | Per month |
|---|---|---|---|
| Light use | 100 W | 3.6 h | $2.02 |
| Typical | 300 W | 6.0 h | $10.10 |
| Heavy use | 500 W | 9.0 h | $25.26 |
Common questions
Does an attic fan lower cooling bills?
Studies show mixed results: it lowers attic temperature, but part of the exhausted air is often pulled from the conditioned house through ceiling leaks. Air-sealing the attic floor first gives more reliable savings.
Cost in every state
Monthly cost of a typical attic fan (300 W, 6h/day) at each state's average residential price, May 2026.
| State | Avg price | Per month |
|---|---|---|
| Alabama | 16.77¢ | $9.19 |
| Alaska | 28.23¢ | $15.47 |
| Arizona | 15.23¢ | $8.34 |
| Arkansas | 14.36¢ | $7.87 |
| California | 33.25¢ | $18.22 |
| Colorado | 16.16¢ | $8.85 |
| Connecticut | 27.37¢ | $15.00 |
| Delaware | 19.38¢ | $10.62 |
| District of Columbia | 25.40¢ | $13.92 |
| Florida | 15.17¢ | $8.31 |
| Georgia | 15.84¢ | $8.68 |
| Hawaii | 52.00¢ | $28.49 |
| Idaho | 12.35¢ | $6.77 |
| Illinois | 23.85¢ | $13.07 |
| Indiana | 18.15¢ | $9.94 |
| Iowa | 14.14¢ | $7.75 |
| Kansas | 15.13¢ | $8.29 |
| Kentucky | 14.98¢ | $8.21 |
| Louisiana | 14.15¢ | $7.75 |
| Maine | 28.63¢ | $15.69 |
| Maryland | 21.77¢ | $11.93 |
| Massachusetts | 28.82¢ | $15.79 |
| Michigan | 22.01¢ | $12.06 |
| Minnesota | 16.95¢ | $9.29 |
| Mississippi | 16.16¢ | $8.85 |
| Missouri | 13.68¢ | $7.49 |
| Montana | 14.67¢ | $8.04 |
| Nebraska | 13.59¢ | $7.45 |
| Nevada | 13.60¢ | $7.45 |
| New Hampshire | 27.33¢ | $14.97 |
| New Jersey | 23.27¢ | $12.75 |
| New Mexico | 14.12¢ | $7.74 |
| New York | 29.93¢ | $16.40 |
| North Carolina | 15.09¢ | $8.27 |
| North Dakota | 13.61¢ | $7.46 |
| Ohio | 19.52¢ | $10.69 |
| Oklahoma | 13.38¢ | $7.33 |
| Oregon | 16.27¢ | $8.91 |
| Pennsylvania | 21.55¢ | $11.81 |
| Rhode Island | 29.46¢ | $16.14 |
| South Carolina | 16.18¢ | $8.86 |
| South Dakota | 15.73¢ | $8.62 |
| Tennessee | 14.47¢ | $7.93 |
| Texas | 16.44¢ | $9.01 |
| Utah | 12.96¢ | $7.10 |
| Vermont | 24.89¢ | $13.64 |
| Virginia | 17.61¢ | $9.65 |
| Washington | 14.95¢ | $8.19 |
| West Virginia | 16.80¢ | $9.20 |
| Wisconsin | 19.74¢ | $10.82 |
| Wyoming | 14.80¢ | $8.11 |
Related calculators
Central air conditioner The biggest single line on most summer power bills.
~3,500 W · 8h/day →
Window air conditioner Cheap to buy; the running cost depends on runtime.
~900 W · 8h/day →
Portable air conditioner Convenient, but the least efficient way to cool a room.
~1,100 W · 8h/day →
Ductless mini-split Inverter compressors sip power once the room is at temperature.
~800 W · 8h/day →
Central heat pump Heats and cools — usually the cheapest electric heat available.
~3,000 W · 6h/day →
Space heater 1,500 watts adds up faster than most people expect.
~1,500 W · 6h/day →
Methodology & sources
Cost = watts ÷ 1,000 × hours × price per kWh. Electricity prices are average residential prices by state from the EIA Electric Power Monthly, Table 5.6.A (May 2026). EIA averages include delivery charges and taxes but are not any specific utility tariff — for an exact figure, use the rate from your own bill. Wattage presets reflect common product ranges; check your appliance's nameplate or a plug-in power meter for its true draw.
Last verified: July 30, 2026. Prices refresh automatically each month when EIA publishes new data.