Cost to Run a 500-watt attic ventilation fan for 7 hours
Running a 500-watt attic ventilation fan for 7 hours uses 3.5 kWh and costs $0.613 at $0.175/kWh. Do that every day and it adds up to $18.38 a month.
Calculate your own cost
- Per hour
- $0.0880.5 kWh
- Per day
- $0.6133.5 kWh
- Per week
- $4.2924.5 kWh
- Per month (30 days)
- $18.38105 kWh
- Per year
- $223.561,278 kWh
Formula: watts ÷ 1,000 × hours × rate. Edit any box and every number updates instantly.
People also ask
How much does a 500-watt attic ventilation fan cost per hour?
At $0.175/kWh, it costs $0.088 per hour. The maths: 500 W ÷ 1,000 = 0.5 kWh per hour, × $0.175 = $0.088.
How much does it cost per month?
Used 7 hours a day for 30 days, it costs about $18.38 per month and uses 105 kWh. Change the hours in the calculator above to match how you use it.
How many kWh does it use?
3.5 kWh per day, 105 kWh per month and 1,278 kWh per year at 7 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 the right control settings and ensure the attic has adequate intake vents. 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 $10.50 and at 30¢ it is $31.50. 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 | 0.5 kWh | $0.088 | $2.63 | $31.94 |
| 2 hours | 1 kWh | $0.175 | $5.25 | $63.88 |
| 3 hours | 1.5 kWh | $0.263 | $7.88 | $95.81 |
| 4 hours | 2 kWh | $0.35 | $10.50 | $127.75 |
| 5 hours | 2.5 kWh | $0.438 | $13.13 | $159.69 |
| 6 hours | 3 kWh | $0.525 | $15.75 | $191.63 |
| 7 hours | 3.5 kWh | $0.613 | $18.38 | $223.56 |
| 8 hours | 4 kWh | $0.70 | $21.00 | $255.50 |
| 9 hours | 4.5 kWh | $0.788 | $23.63 | $287.44 |
| 10 hours | 5 kWh | $0.875 | $26.25 | $319.38 |
| 11 hours | 5.5 kWh | $0.963 | $28.88 | $351.31 |
| 12 hours | 6 kWh | $1.05 | $31.50 | $383.25 |
| 13 hours | 6.5 kWh | $1.14 | $34.13 | $415.19 |
| 14 hours | 7 kWh | $1.23 | $36.75 | $447.13 |
| 15 hours | 7.5 kWh | $1.31 | $39.38 | $479.06 |
| 16 hours | 8 kWh | $1.40 | $42.00 | $511.00 |
| 17 hours | 8.5 kWh | $1.49 | $44.63 | $542.94 |
| 18 hours | 9 kWh | $1.58 | $47.25 | $574.88 |
| 19 hours | 9.5 kWh | $1.66 | $49.88 | $606.81 |
| 20 hours | 10 kWh | $1.75 | $52.50 | $638.75 |
| 21 hours | 10.5 kWh | $1.84 | $55.13 | $670.69 |
| 22 hours | 11 kWh | $1.93 | $57.75 | $702.63 |
| 23 hours | 11.5 kWh | $2.01 | $60.38 | $734.56 |
| 24 hours | 12 kWh | $2.10 | $63.00 | $766.50 |
How we worked it out
- Energy per hour: 500 W ÷ 1,000 = 0.5 kWh
- Cost per hour: 0.5 kWh × $0.175 = $0.088
- Cost per day: × 7 hours = $0.613
- Month and year: × 30 days = $18.38, × 365 days = $223.56
What it costs in different places
Same 500-watt attic ventilation fan, 7 hours a day. Only the local electricity rate changes.
| Place | Rate per kWh | Cost per month |
|---|---|---|
| United States | $0.175 | $18.38 |
| California | $0.32 | $33.60 |
| Texas | $0.155 | $16.28 |
| New York | $0.25 | $26.25 |
| Florida | $0.155 | $16.28 |
| Illinois | $0.17 | $17.85 |
| Pennsylvania | $0.18 | $18.90 |
| Ohio | $0.17 | $17.85 |
| Washington | $0.115 | $12.08 |
About attic ventilation fan running costs
Attic fans use a motor for ventilation. Actual power depends on fan size and whether a thermostat or humidistat controls it.
Typical sizes: 150 W, 300 W, 500 W, 800 W.
How to spend less: Use the right control settings and ensure the attic has adequate intake vents.
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.