Heating & Cooling · South
Cost to run a box fan in Kentucky
At Kentucky’s average residential rate of 13.80¢ per kWh, a box fan drawing 75W for 8 hours a day, at a 100% duty cycle, costs about $2.52 per 30.44 use days. Change the numbers below to match how you actually use yours.
For seasonal use in Kentucky, enter the days you actually run this box fan in the calculator. The reference tables assume 365 use days; they are not a forecast of local weather, your thermostat settings or your annual bill.
Box Fan electricity cost calculator
Use watts and running time, or enter energy from a label, meter or completed load. Your inputs stay on this device.
Enter a number within each field’s limits to calculate your cost.
Your estimated energy cost
219 kWh across 365 use days per year
Power mode includes your selected duty cycle. The monthly figure assumes 30.44 use days; the annual total uses your selected use days. These are estimates at the entered rate.
Energy charges only. Fixed utility fees, purchase, installation and maintenance are excluded. See the calculation method and sources.
Why the cost differs in Kentucky
Kentucky has the 8th cheapest residential electricity of the 50 US states and Washington, DC we track, at 13.80¢ per kWh against a national average of 18.16¢. That is -24.0% compared with the national figure. Kentucky built its historically low rates on cheap coal generation, and those rates are now rising as coal plants retire and replacement capacity is added. Retail service is regulated. Electric heating is common, so winter carries substantial load, while humid summers drive a cooling peak. Bills here are more exposed to the generation transition than in most states.
For this appliance specifically, the difference works out to a saving of $9.55 a year against what the same box fan would cost at the national average rate. Run the identical appliance in Hawaii and it would cost $103 a year; in Nevada it would cost $27.86. That spread of $75.47 is entirely down to location.
Reducing use by 100 kWh would save $13.80 in energy charges at Kentucky's average rate, compared with $18.16 at the US average. Whether a replacement appliance pays for itself also depends on its purchase price and the energy it actually saves.
Use the energy and delivery price that applies to your own utility plan in Kentucky. If your plan has time-of-use prices, calculate each period separately or use a rate weighted by the electricity used in each period. Fixed monthly fees are outside this appliance energy-cost estimate.
| Location | Rate | Per month | Per year |
|---|---|---|---|
| Kentucky this page | 13.80¢ | $2.52 | $30.22 |
| US average | 18.16¢ | $3.32 | $39.77 |
| Nevada cheapest state | 12.72¢ | $2.32 | $27.86 |
| Hawaii most expensive | 47.18¢ | $8.62 | $103 |
Kentucky electricity rate trend
Rates in Kentucky have moved from 13.40¢ to 13.80¢ per kWh between September 2025 and August 2026. The national residential average changed +3.4% from the same month a year earlier.
2025-09 to 2026-08 · cents per kWh
About running a box fan
A box fan is one of the cheapest comfort appliances to run, typically costing a few dollars per month even in continuous use. Used to exhaust hot air at night it can measurably reduce air conditioner runtime.
How we worked this out
The arithmetic is simple and we would rather show it than hide it. Divide watts by 1,000 to get kilowatts, multiply by hours of use and by the duty cycle to get kilowatt-hours, then multiply by your rate:
75W ÷ 1000 × 8h = 0.600 kWh/day × 13.80¢ = $0.083 per day
One honest caveat: Kentucky’s figure is a state average published by the EIA. Your own utility’s tariff, any time-of-use pricing, fixed monthly service charges and local taxes all shift the real number. Put your actual per-kWh rate into the calculator above for a figure that reflects your bill.
How to estimate your box fan electricity use
Box-fan running cost is usually a straightforward wattage-times-hours calculation, but the speed setting matters. Use the actual electrical draw for low, medium or high speed rather than assuming all settings use the nameplate maximum.
These examples assume a constant 75W draw. They are calculated scenarios, not measurements of a particular fan.
- For an illustrative steady 75W fan, eight hours uses 0.6 kWh. At $0.20/kWh that costs $0.12.
- Running the same 75W draw for 24 hours uses 1.8 kWh and costs $0.36 at that illustrative rate. Thirty days at this schedule costs $10.80; the calculator monthly equivalent in watts-and-hours mode uses 30.44 days.
- Set duty to 100% for steady operation during the selected hours. If a timer shuts the fan off, reduce the hours or the duty fraction, not both for the same off-time.
- Use the actual number of seasonal use-days when estimating annual fan cost.
Calculation and data sources
Daily kWh = watts ÷ 1,000 × hours × duty cycle ÷ 100. Multiply kWh by your rate in dollars per kWh to get cost. The wattage, hours and duty cycle above are editable example assumptions, not EIA measurements of this appliance.
The US and state average prices come from the EIA for August 2026. A state average is a starting point; your bill is the better source for your tariff.
Questions about box fan running costs
How much electricity does a box fan use?
In this example, 75 watts at a 100% duty cycle uses 0.075 kWh per scheduled hour. At 8.00 hours per day, that is 0.600 kWh per use day. Your model and operating conditions can differ.
How much does it cost to run a box fan for an hour?
The default example costs $0.010 per scheduled hour at the Kentucky average of 13.80¢/kWh for August 2026. This includes the selected duty cycle. Enter your watts, duty cycle and electricity price for your own estimate.
Does the annual cost assume I use it every day?
The reference tables use 365 days at the stated daily hours; monthly figures use 30.44 days. These are comparison scenarios, not forecasts. For a heater used on 90 days, enter 90 use days per year in the calculator.
Why does electricity running cost vary by state?
For August 2026, the EIA state averages range from 12.72¢/kWh in Nevada to 47.18¢/kWh in Hawaii. Equal electricity use costs more at a higher rate. Your utility tariff can differ from the state average.
How much does a box fan cost to run 24/7?
At an illustrative constant 75W it uses 1.8 kWh per day. Multiply by your electricity rate; at $0.20/kWh that is $0.36 per day or $10.80 over 30 days.
How do I calculate a box fan on low speed?
Enter the watts specified or measured at low speed, together with your hours and price per kWh. Do not assume the highest-speed wattage applies to every setting.
Why is the monthly calculator result slightly above a 30-day example?
In watts-and-hours mode, the monthly equivalent uses 30.44 days. A 30-day example uses exactly 30 days; both use the same daily energy formula.