When a heatwave hits and the fan goes on, a quiet worry follows it: is this thing running up the bill while I sleep? The reassuring answer is no. A fan is one of the cheapest appliances in the house to run, costing roughly a penny an hour, so even left on all night it adds only a few pence. This guide gives the real figures by fan type, so you can stop worrying and leave it on.
The short answer. Most fans draw between about 5 and 100 watts, so at the standard electricity rate of about 26p a unit they cost from a fraction of a penny up to around 2.6p an hour. A typical pedestal or tower fan at 50 watts costs about 1.3p an hour, so running it for a twelve-hour night costs roughly 16p. Over a whole hot month of nightly use that is only a few pounds. A fan is about the cheapest cooling there is.
Why a fan is so cheap to run
A fan does not cool the air, it moves it, and moving air is a light job for an electric motor. That breeze cools you by helping sweat evaporate from your skin, which is why a fan feels cooling even though the room temperature has not changed. Because all the motor is doing is spinning a blade, the power draw is tiny, measured in tens of watts rather than the kilowatts an air conditioner pulls to actually remove heat from the room. That difference, a fan moving air versus a compressor shifting heat, is the whole reason one costs pennies and the other costs pounds.
What different fans cost
Fans vary in size from a tiny clip-on to a big floor blower, and the power draw varies with them, but every one of them is cheap. The table uses the standard price-cap rate of about 26p per kWh, current in mid 2026. To find your own fan's figure, look for the wattage printed on the motor housing or in the manual, or put it through the running cost calculator.
| Fan type | Typical power | Cost per hour | Cost for a 12-hour night |
|---|---|---|---|
| Small USB or clip-on fan | 5 to 15 W | ~0.1p to 0.4p | ~2p to 5p |
| Ceiling fan | 15 to 30 W | ~0.4p to 0.8p | ~5p to 9p |
| Pedestal or tower fan | 40 to 60 W | ~1.0p to 1.6p | ~13p to 19p |
| Large floor or industrial fan | 100 W | ~2.6p | ~31p |
At an example 26p per kWh. Even the thirstiest household fan running all night costs about the price of a chocolate bar, and the small ones cost almost nothing. Lower fan speeds draw less power still.
A whole night, a whole summer
Put it in terms of real use. Leaving a 50-watt pedestal fan running every night through a hot month, say twelve hours a night for thirty nights, uses about 18 kilowatt-hours, which at 26p comes to under 5 pounds for the month. A small bedside fan costs a fraction of that. Even if you ran fans in two rooms all summer, the total would be a handful of pounds, not the scary number people imagine. Set against the cost of cooling those rooms with air conditioning, which could run to that much in a couple of days, the fan is almost free.
Getting the most from a cheap breeze
Because a fan only cools the person feeling it, the one rule is to run it where someone is, not in an empty room, where it does nothing but spend its pennies for no benefit. Beyond that, a fan earns its keep helping move air through the house: placed in an open window in the evening it draws cool outside air in, or pushes warm air out, flushing the day's heat as the keeping cool guide describes. A bowl of ice in front of the fan adds a brief extra chill on the very hottest days. And a ceiling fan, being permanently sited and efficient, is a cheap way to keep a room comfortable for the lowest running cost of all.
When a fan is not enough
A fan has one limit: it cannot lower the air temperature, only make moving air feel cooler on the skin. On the rare days when the air itself is simply too hot, a fan blowing hot air around brings little relief, and that is the point at which real cooling earns its much higher cost. But those days are few, and the honest order is to exhaust the free measures and the cheap fan first, reserving the expensive compressor for when nothing else will do. For the great majority of warm evenings, a fan at a penny an hour is all the cooling the bill needs to carry.
The bottom line
A fan costs roughly a penny an hour to run, so a whole night is a few pence and a whole summer a few pounds, because all it does is move air rather than chill it. Leave it on while you are in the room without a second thought, use it to flush cool night air through the house, and keep the costly air conditioning for the handful of days a fan genuinely cannot cope with. Of all the ways to feel cooler, the fan is the one your bill will never notice.