How Much Electricity Does A Bathroom Exhaust Fan Use?
A bathroom exhaust fan typically uses about 25 watts while running. At 1 hours a day that is 0.03 kWh per day, 0.75 kWh per month and 9.13 kWh per year.
Calculate your own cost
- Per hour
- $0.0040.03 kWh
- Per day
- $0.0040.03 kWh
- Per week
- $0.0310.18 kWh
- Per month (30 days)
- $0.1310.75 kWh
- Per year
- $1.609.13 kWh
Formula: watts ÷ 1,000 × hours × rate. Edit any box and every number updates instantly.
People also ask
How much does a 25-watt bathroom exhaust fan cost per hour?
At $0.175/kWh, it costs $0.004 per hour. The maths: 25 W ÷ 1,000 = 0.03 kWh per hour, × $0.175 = $0.004.
How much does it cost per month?
Used 1 hours a day for 30 days, it costs about $0.131 per month and uses 0.75 kWh. Change the hours in the calculator above to match how you use it.
How many kWh does it use?
0.03 kWh per day, 0.75 kWh per month and 9.13 kWh per year at 1 hours a day. A kWh is one kilowatt (1,000 W) used for one hour. It is the unit on your electricity bill.
How can I lower the cost?
Use a timer and run the fan long enough to remove moisture, not all day. Check your bill for the exact rate and enter it above.
Does my electricity rate change the answer?
Yes, a lot. At 10¢ per kWh the monthly cost is $0.075 and at 30¢ it is $0.225. Find your rate on your bill (total cost ÷ kWh used) and type it into the calculator.
Cost by hours of use
| Used per day | Energy per day | Cost per day | Cost per month | Cost per year |
|---|---|---|---|---|
| 1 hour | 0.03 kWh | $0.004 | $0.131 | $1.60 |
| 2 hours | 0.05 kWh | $0.009 | $0.263 | $3.19 |
| 3 hours | 0.08 kWh | $0.013 | $0.394 | $4.79 |
| 4 hours | 0.1 kWh | $0.018 | $0.525 | $6.39 |
| 5 hours | 0.13 kWh | $0.022 | $0.656 | $7.98 |
| 6 hours | 0.15 kWh | $0.026 | $0.788 | $9.58 |
| 7 hours | 0.18 kWh | $0.031 | $0.919 | $11.18 |
| 8 hours | 0.2 kWh | $0.035 | $1.05 | $12.78 |
| 9 hours | 0.23 kWh | $0.039 | $1.18 | $14.37 |
| 10 hours | 0.25 kWh | $0.044 | $1.31 | $15.97 |
| 11 hours | 0.28 kWh | $0.048 | $1.44 | $17.57 |
| 12 hours | 0.3 kWh | $0.053 | $1.58 | $19.16 |
| 13 hours | 0.33 kWh | $0.057 | $1.71 | $20.76 |
| 14 hours | 0.35 kWh | $0.061 | $1.84 | $22.36 |
| 15 hours | 0.38 kWh | $0.066 | $1.97 | $23.95 |
| 16 hours | 0.4 kWh | $0.07 | $2.10 | $25.55 |
| 17 hours | 0.43 kWh | $0.074 | $2.23 | $27.15 |
| 18 hours | 0.45 kWh | $0.079 | $2.36 | $28.74 |
| 19 hours | 0.48 kWh | $0.083 | $2.49 | $30.34 |
| 20 hours | 0.5 kWh | $0.088 | $2.63 | $31.94 |
| 21 hours | 0.53 kWh | $0.092 | $2.76 | $33.53 |
| 22 hours | 0.55 kWh | $0.096 | $2.89 | $35.13 |
| 23 hours | 0.58 kWh | $0.101 | $3.02 | $36.73 |
| 24 hours | 0.6 kWh | $0.105 | $3.15 | $38.33 |
How we worked it out
- Energy per hour: 25 W ÷ 1,000 = 0.03 kWh
- Cost per hour: 0.03 kWh × $0.175 = $0.004
- Cost per day: × 1 hours = $0.004
- Month and year: × 30 days = $0.131, × 365 days = $1.60
About bathroom exhaust fan running costs
Bathroom exhaust fans use a small motor, but long runtimes add to annual energy use. Larger or heat-lamp models draw much more.
Typical sizes: 15 W, 25 W, 40 W, 70 W.
How to spend less: Use a timer and run the fan long enough to remove moisture, not all day.
What this estimate assumes
- The appliance draws its full stated wattage the whole time it is on. Real units with a thermostat cycle off and cost less.
- Wattage is the typical label value, not a measured value. Check the label on your own appliance.
- The rate is an approximate residential average. Your bill may include fixed fees, tiers or time-of-use pricing. Edit the rate above.
- A month is 30 days and a year is 365 days.