How much does it cost to run a bathroom exhaust fan?
A bathroom exhaust fan costs about 0.3¢ per hour, 0.3¢ a day, $0.08 a month and $1 a year at typical use (1 hour a day) and the U.S. average rate of 17.99¢/kWh. Modern bathroom fans draw 5-25 W; older units use 40-60 W. The bigger cost is removing heated or cooled air when left running for hours.
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Cost by setting
| Setting | Watts | Per hour | Per day | Per month | Per year |
|---|---|---|---|---|---|
| ENERGY STAR DC fan | 8 | 0.1¢ | 0.1¢ | $0.04 | $1 |
| Standard fan | 15 | 0.3¢ | 0.3¢ | $0.08 | $1 |
| Older fan | 50 | 0.9¢ | 0.9¢ | $0.27 | $3 |
| Fan with light and heater | 120 | 2.2¢ | 2.2¢ | $0.66 | $8 |
At 1 hour a day and 17.99¢/kWh.
Cost by hours of use
| Hours per day | kWh/day | Per day | Per month | Per year (all year) |
|---|---|---|---|---|
| 1 hour | 0.01 | 0.3¢ | $0.08 | $1 |
| 2 hours | 0.03 | 0.5¢ | $0.16 | $2 |
| 4 hours | 0.06 | 1.1¢ | $0.33 | $4 |
| 8 hours | 0.12 | 2.2¢ | $0.66 | $8 |
| 12 hours | 0.18 | 3.2¢ | $0.99 | $12 |
| 24 hours | 0.36 | 6.5¢ | $1.97 | $24 |
Cost to run a bathroom exhaust fan in every state
The same bathroom exhaust fan costs $1 a year in North Dakota and $2 in Hawaii, at each state's average residential rate (12 months ending July 2026).
| State | Rate | Per hour | Per month | Per year |
|---|---|---|---|---|
| North Dakota | 12.32¢ | 0.2¢ | $0.06 | $1 |
| Idaho | 12.65¢ | 0.2¢ | $0.06 | $1 |
| Nebraska | 12.86¢ | 0.2¢ | $0.06 | $1 |
| Louisiana | 12.99¢ | 0.2¢ | $0.06 | $1 |
| Utah | 13.32¢ | 0.2¢ | $0.06 | $1 |
| Nevada | 13.36¢ | 0.2¢ | $0.06 | $1 |
| Arkansas | 13.43¢ | 0.2¢ | $0.06 | $1 |
| Tennessee | 13.56¢ | 0.2¢ | $0.06 | $1 |
| Oklahoma | 13.70¢ | 0.2¢ | $0.06 | $1 |
| Montana | 13.84¢ | 0.2¢ | $0.06 | $1 |
| Kentucky | 13.92¢ | 0.2¢ | $0.06 | $1 |
| Missouri | 13.95¢ | 0.2¢ | $0.06 | $1 |
| Wyoming | 14.01¢ | 0.2¢ | $0.06 | $1 |
| Washington | 14.12¢ | 0.2¢ | $0.06 | $1 |
| Iowa | 14.13¢ | 0.2¢ | $0.06 | $1 |
| South Dakota | 14.20¢ | 0.2¢ | $0.06 | $1 |
| Mississippi | 14.77¢ | 0.2¢ | $0.07 | $1 |
| North Carolina | 14.77¢ | 0.2¢ | $0.07 | $1 |
| Kansas | 15.09¢ | 0.2¢ | $0.07 | $1 |
| Georgia | 15.12¢ | 0.2¢ | $0.07 | $1 |
| New Mexico | 15.32¢ | 0.2¢ | $0.07 | $1 |
| Florida | 15.39¢ | 0.2¢ | $0.07 | $1 |
| Arizona | 15.40¢ | 0.2¢ | $0.07 | $1 |
| West Virginia | 15.48¢ | 0.2¢ | $0.07 | $1 |
| Oregon | 15.50¢ | 0.2¢ | $0.07 | $1 |
| South Carolina | 15.64¢ | 0.2¢ | $0.07 | $1 |
| Texas | 15.96¢ | 0.2¢ | $0.07 | $1 |
| Minnesota | 16.22¢ | 0.2¢ | $0.07 | $1 |
| Alabama | 16.44¢ | 0.2¢ | $0.08 | $1 |
| Virginia | 16.48¢ | 0.2¢ | $0.08 | $1 |
| Colorado | 16.58¢ | 0.2¢ | $0.08 | $1 |
| Indiana | 16.94¢ | 0.3¢ | $0.08 | $1 |
| Delaware | 17.79¢ | 0.3¢ | $0.08 | $1 |
| Ohio | 18.25¢ | 0.3¢ | $0.08 | $1 |
| Wisconsin | 18.74¢ | 0.3¢ | $0.09 | $1 |
| Illinois | 18.79¢ | 0.3¢ | $0.09 | $1 |
| Pennsylvania | 20.70¢ | 0.3¢ | $0.09 | $1 |
| Maryland | 21.03¢ | 0.3¢ | $0.10 | $1 |
| Michigan | 21.05¢ | 0.3¢ | $0.10 | $1 |
| New Jersey | 23.78¢ | 0.4¢ | $0.11 | $1 |
| Vermont | 23.80¢ | 0.4¢ | $0.11 | $1 |
| District of Columbia | 24.20¢ | 0.4¢ | $0.11 | $1 |
| New Hampshire | 26.67¢ | 0.4¢ | $0.12 | $1 |
| Alaska | 26.85¢ | 0.4¢ | $0.12 | $1 |
| Connecticut | 27.99¢ | 0.4¢ | $0.13 | $2 |
| New York | 28.39¢ | 0.4¢ | $0.13 | $2 |
| Rhode Island | 29.27¢ | 0.4¢ | $0.13 | $2 |
| Maine | 29.31¢ | 0.4¢ | $0.13 | $2 |
| Massachusetts | 30.43¢ | 0.5¢ | $0.14 | $2 |
| California | 32.99¢ | 0.5¢ | $0.15 | $2 |
| Hawaii | 43.51¢ | 0.7¢ | $0.20 | $2 |
How to cut the cost
- Run it during the shower and for 20 minutes after, then shut it off.
- Install a humidity-sensing or 20-60 minute timer switch so it never runs all day.
- Clean the grille and blower yearly; dust cuts airflow and makes it run longer.
- Replace a 50 W fan with an ENERGY STAR model using under 10 W if it runs often.
Cheaper ways to get the job done
Prevents the fan exhausting heated or cooled air for hours.
See options on AmazonRuns only until moisture is cleared.
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Compare with similar appliances
| Appliance | Watts | Typical use | Per month | Per year |
|---|---|---|---|---|
| Bathroom exhaust fan | 15 | 1 hour a day | $0.08 | $1 |
| Heat lamp | 250 | 30 minutes a day | $0.68 | $8 |
| Heated towel rack | 100 | 6 hours a day | $2.63 | $32 |
| Attic fan | 300 | 8 hours a day for 5 months a year | $9.20 | $46 |
| Dehumidifier | 500 | 24 hours a day for 6 months a year | $26.28 | $158 |
| Whole-house humidifier | 20 | 12 hours a day for 5 months a year | $0.66 | $3 |
| Desk fan | 25 | 8 hours a day, 5 days a week for 5 months a year | $0.78 | $4 |
Head-to-head comparisons
Frequently asked questions
How much does it cost to run a bathroom exhaust fan per hour?
A bathroom exhaust fan drawing 15 watts uses 0.01 kWh per hour. At the U.S. average of 17.99¢/kWh that's 0.3¢ per hour. In North Dakota (12.32¢) it's 0.2¢. In Hawaii (43.51¢) it's 0.7¢.
How much does it cost to run a bathroom exhaust fan per month?
At typical use (1 hour a day), a bathroom exhaust fan costs about $0.08 a month and $1 a year, at the U.S. average rate. Enter your ZIP in the calculator above for your utility's rate.
How many watts does a bathroom exhaust fan use?
Most bathroom exhaust fans use 5 to 120 watts, depending on the setting (energy star dc fan 8 W, standard fan 15 W, older fan 50 W, fan with light and heater 120 W). Check the label on the back or bottom for your model's exact rating.
How many kWh does a bathroom exhaust fan use?
About 0.01 kWh a day and 5 kWh a year at typical use (1 hour a day).
Does a bathroom exhaust fan use a lot of electricity?
No. At about 5 kWh a year it's a small share (0.1%) of the average U.S. home's 10,492 kWh.
Is it cheaper to run a bathroom exhaust fan or a heat lamp?
At typical use, a bathroom exhaust fan costs about $1 a year versus $8 for a heat lamp. So the bathroom exhaust fan is cheaper by about $7 a year. Use the comparison table above to compare them at your own settings.
How can I lower the cost of running a bathroom exhaust fan?
- Run it during the shower and for 20 minutes after, then shut it off.
- Install a humidity-sensing or 20-60 minute timer switch so it never runs all day.
- Clean the grille and blower yearly; dust cuts airflow and makes it run longer.
Rates updated 2026-10-21: EIA data through July 2026. Typical wattage and usage reviewed against DOE, ENERGY STAR and manufacturer specs. Methodology.