How much does a whole-house fan cost to run in Missouri?
$15 a month while in use, May to September
- A day of use
- $0.48
- An hour of running
- $0.08
- A year (season only)
- $73.71
495 W, 6 hours a day in the evening, May to September, at Missouri’s average rate of 16.2¢ per kWh (EIA, June 2026). How we calculate this
Change the watts, hours or rate
What it costs at other usage levels
| Use | A day | A month in use | A year |
|---|---|---|---|
| 1 hour a day | $0.08 | $2.44 | $12.28 |
| 2 hours a day | $0.16 | $4.88 | $24.57 |
| 4 hours a day | $0.32 | $9.77 | $49.14 |
| 6 hours a day typical | $0.48 | $14.65 | $73.71 |
| 8 hours a day | $0.64 | $19.54 | $98.27 |
| 24 hours a day | $1.93 | $58.61 | $294.82 |
Models range from 240 W to 750 W (Virginia Cooperative Extension). We use 495 W, the middle of that range.
Missouri compared with other states
Missouri’s residential rate is the 25th cheapest of 51 states and DC, 2.1¢ below the US average of 18.3¢ (−12%). Missouri’s rate is up 0.3¢ from June 2025 (15.9¢, +1.9%).
Ways to spend less
- Run it only when the outdoor air is cooler than indoors, usually evening and early morning.
- Open windows before switching it on so it pulls in outside air instead of straining.
- Run it one hour less a day. Saves about $2.44 a month in season.
Questions
How much does it cost to run a whole-house fan per hour?
About $0.08 an hour in Missouri. A whole-house fan at 495 W uses 0.495 kWh per hour, and at Missouri’s average of 16.2¢ per kWh that comes to $0.08.
How much does a whole-house fan add to your electric bill?
Used 6 hours a day in the evening, May to September, about $14.65 a month while it is in use in Missouri, or $73.71 a year across the May to September season.
How much does it cost to run a whole-house fan 24 hours a day?
Running nonstop, a whole-house fan would use 11.9 kWh a day and cost $1.93 a day, or $58.61 over an average month in Missouri.
How many watts does a whole-house fan use?
Models range from 240 W to 750 W (Virginia Cooperative Extension). We use 495 W, the middle of that range. Check the label on yours: cost scales directly with watts, so a 20% lower wattage means a 20% lower bill.
Why does a whole-house fan cost more or less to run in Missouri than elsewhere?
Missouri’s residential rate is the 25th cheapest of 51 states and DC, 2.1¢ below the US average of 18.3¢ (−12%). Missouri’s rate is up 0.3¢ from June 2025 (15.9¢, +1.9%). The appliance uses the same energy everywhere; only the price per kWh changes.
Sources
- Virginia Cooperative Extension: Estimating appliance and home electronic energy use (reproduces U.S. Department of Energy sample wattages)
- Penn State EGEE 102: Typical range of power consumption (wattage)
- U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A: average price of electricity to ultimate customers, residential, June 2026 Figures transcribed from republications of this table on September 26, 2026; pending direct verification from the EIA API.
- Carrier page: June 2026 residential average price, citing EIA Electric Power Monthly Table 5.6.A
Usage assumptions (hours a day, season) are ours and listed on the methodology page. Found an error? Tell us.