hvac · 100W typical

Running a box fan costs about $3.96/month.

That's the typical box fan at 100W, run 8 hours a day at the US-average rate of 16.5¢/kWh. Change any of those and the number moves — use the calculator below to see yours.

Estimated cost

$3.96/month

$0.13 per day$48.18 per year24.0 kWh monthly

Wattage

Hours / day

Your rate

Full-power draw for 8 hours at 16.5¢/kWh.

How you use it

Cost shifts with how long it's on.

The same box fan can cost very different amounts depending on usage patterns. Three common scenarios, at the US-average rate.

bedroom white noise

$3.96

per month

running overnight for airflow and sound

8 hrs/day·$48.18/yr

daytime cooling

$4.95

per month

single-room ventilation during summer days

10 hrs/day·$60.23/yr

whole-house exhaust

$1.98

per month

window-mounted at night to pull in cool air

4 hrs/day·$24.09/yr

Where you live

$7.18 spread between the cheapest and priciest states.

Same appliance, same hours of use, different zip code — the monthly cost varies this much.

State	Rate	Monthly	Yearly
Hawaii	41.2¢	$9.89	$120.30
California	31.4¢	$7.54	$91.69
Massachusetts	30.8¢	$7.39	$89.94
Connecticut	28.7¢	$6.89	$83.80
Rhode Island	27.9¢	$6.70	$81.47
New Hampshire	24.6¢	$5.90	$71.83
Alaska	24.3¢	$5.83	$70.96
New York	22.3¢	$5.35	$65.12
Maine	22.1¢	$5.30	$64.53
Vermont	21.5¢	$5.16	$62.78
Michigan	19.3¢	$4.63	$56.36
New Jersey	19.1¢	$4.58	$55.77
Maryland	18.4¢	$4.42	$53.73
Pennsylvania	18.1¢	$4.34	$52.85
District of Columbia	17.8¢	$4.27	$51.98
Wisconsin	17.4¢	$4.18	$50.81
Delaware	17.2¢	$4.13	$50.22
Illinois	16.9¢	$4.06	$49.35
Ohio	16.6¢	$3.98	$48.47
Nevada	16.3¢	$3.91	$47.60
Indiana	15.8¢	$3.79	$46.14
Virginia	15.7¢	$3.77	$45.84
Minnesota	15.6¢	$3.74	$45.55
Colorado	15.4¢	$3.70	$44.97
Alabama	15.2¢	$3.65	$44.38
West Virginia	15.2¢	$3.65	$44.38
Florida	15.1¢	$3.62	$44.09
New Mexico	14.8¢	$3.55	$43.22
Texas	14.8¢	$3.55	$43.22
Arizona	14.7¢	$3.53	$42.92
South Carolina	14.7¢	$3.53	$42.92
Kansas	14.6¢	$3.50	$42.63
Georgia	14.2¢	$3.41	$41.46
Iowa	14.1¢	$3.38	$41.17
North Carolina	13.9¢	$3.34	$40.59
Missouri	13.6¢	$3.26	$39.71
Oregon	13.4¢	$3.22	$39.13
Tennessee	13.3¢	$3.19	$38.84
Kentucky	13.2¢	$3.17	$38.54
Mississippi	13.1¢	$3.14	$38.25
Oklahoma	13.1¢	$3.14	$38.25
South Dakota	12.7¢	$3.05	$37.08
Montana	12.4¢	$2.98	$36.21
Nebraska	12.2¢	$2.93	$35.62
Arkansas	12.1¢	$2.90	$35.33
Washington	12.1¢	$2.90	$35.33
Louisiana	11.9¢	$2.86	$34.75
Wyoming	11.6¢	$2.78	$33.87
North Dakota	11.5¢	$2.76	$33.58
Utah	11.4¢	$2.74	$33.29
Idaho	11.3¢	$2.71	$33.00

Efficient vs. inefficient

A $69.86/year difference across the wattage range.

Swapping a high-draw model for an efficient one pays for itself. Here's what that looks like annually at typical usage.

Most efficient

55W

$2.18 per month

$26.50 per year

Typical

100W

$3.96 per month

$48.18 per year

High draw

200W

$7.92 per month

$96.36 per year

When it hits hardest

summer peak

Heaviest June-September; some year-round white-noise use.

Ways to cut the cost

1
Use lowest speed that still moves enough air
Cuts wattage 40-50% vs. high setting
2
Run at night with windows open to pull in cool outside air
Can delay AC season by 2-4 weeks
3
Turn off when the room is empty
Box fans still draw 80-100W even when no one benefits

Real-world wattages

Pulled from actual spec sheets.

Brand	Model	Watts
Lasko	3723 20 in	90W
Holmes	HBF2001A	100W
Genesis	20 in Box Fan	100W

Picks that actually move the needle

Three products worth comparing if you're thinking about upgrading or supplementing what you have.

Some links below are affiliate links. If you buy, we may earn a small commission — it never changes the price you pay, and we only recommend picks we would stand behind.

Lasko 3723 20 in Box Fan

Classic 90W box fan, affordable workhorse

$25-35

Corsi-Rosenthal Box Fan Filter Kit

Turns any box fan into a room air purifier

$45-60

Smart Plug with Energy Monitor

Schedule off-time if you leave fans running

$18-25