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How many watts does a fan use?

A fan draws 5–125 watts while running, which is 0.04–1 amps on a 120 V circuit.

Fan watts, amps and circuit

Typical power use of a fan
Running watts5–125 W
Voltage120 V
Running amps0.04–1 A
Circuitstandard 120 V outlet

Also called: box fan, small fan, pedestal fan, tower fan, desk fan.

Fan watts by size and type

Running and starting watts of fan types
Size or typeRunning watts, WVolts, VAmps, AStarting watts, W
Fan5–1251200.04–1—
Small desk fan16–361200.13–0.3—
Tower fan5–711200.04–0.59—
Pedestal fan40–1251200.33–1—
20-inch box fan70–1201200.58–1—
050100150Watts, WSize or typeFanFan, Running watts: 5–1255–125Small desk fanSmall desk fan, Running watts: 16–3616–36Tower fanTower fan, Running watts: 5–715–71Pedestal fanPedestal fan, Running watts: 40–12540–12520-inch box fan20-inch box fan, Running watts: 70–12070–1200255075100125Watts, WSize or typeFanFan, Running watts: 5–1255–125Small desk fanSmall desk fan, Running watts: 16–3616–36Tower fanTower fan, Running watts: 5–715–71Pedestal fanPedestal fan, Running watts: 40–12540–12520-inch box fan20-inch box fan, Running watts: 70–12070–120
Watts of fan types. The lighter part of a bar is the upper end of the typical range.

What size generator runs a fan?

A fan needs a generator that supplies at least 125 running watts. A 2,000 W generator covers it with its running rating alone; add the watts of anything else you run at the same time.

How long a portable power station runs a fan

Runtime of a fan on a portable power station, at 85% inverter efficiency
Battery capacity, WhAt 125 W, hAt 5 W, h
5003.485
1,0006.8170
2,00013.6340
3,60024.5612

A 500 Wh portable power station runs a fan drawing 125 W for about 3.4 hours at 85% inverter efficiency. Runtime = capacity × 85% ÷ watts; the 85% efficiency is an assumption. The power station's AC output must be at least 125 W.

What it costs to run a fan

Running a fan at 65 W, the middle of its 5–125 W range, for one hour a day uses 23.7 kWh a year. That costs about $4.27 a year at $0.18 per kWh, the US average residential price for August 2026.

W
h
$/kWh

Your bill's total ÷ kWh used. 0.18 is the US residential average.

Result
$0.36 / month
Per day
$0.01
Per year
$4.27
Energy per day
0.07 kWh
Energy per month
2 kWh

How it is calculated

  1. kWh per day = 65 W × 1 h ÷ 1,000 = 0.065
  2. Per month = 0.065 kWh × 30.4 days × $0.18 = $0.36

What affects fan power use

Blade size and speed setting drive the number, and the high setting draws more than the low setting. Fans with DC motors use less than fans with AC motors. A fan moves air but does not cool it, so it uses far less power than an air conditioner.

How the amps are calculated

Amps = watts ÷ volts. For 125 W at 120 V that is 1 A. The 5–125 W range covers typical models; the nameplate on a fan gives the exact figure.

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