How much does it cost to leave a fan on all night?


IT’S set to be a scorcher with the sun shining and temperatures soaring to 35C.

Sweltering Brits will be turning to fans to keep cool in the heat – but how much could it add to energy bills?

We take a look how much it costs to use a fan in a heatwave

Summer months are when you can save on your bills, turning to air drying clothes instead of costly tumble dryers, for instance

But while you’ll keep costs down with the heating off, you’re likely switching the fan on instead.

Energy bills soared by 54% in April meaning running the device will cost you more than it did last year.

The average annual household bill for gas and electric now stands at £1,971 a year if you’re on a price-capped tariff, like more than 20million other people.

The price cap limits the unit cost of electricity, but the exact amount you pay depends on your usage.

If you’re getting hot under the collar about rising costs, we explain how much you could be paying to keep cool.

How much energy does a fan use?

To work this out you need to find out how much electricity your fan uses. Finding out the “wattage” of a fan will give you the answer and tell you the amount of power it’s using.

Then you need to find the total output you will have to turn that wattage into kilowatt hours.

There’s a bit of maths involved as first you divide the kilowatt hours by 1,000.

This will give you how much output is used in one hour.

So if your fan is 70 watts output on its high setting and you always use this, divide 70 by 1000 = 0.07.

Then multiply this number by the number of hours you’ve used the fan. For example, if you’re using it for 12 hours at a time, then 0.07kW x 12 hours will mean 0.84kW output.

How much does it cost to leave a fan on all night?

Now that you know your kilowatt output, you need to times it by the amount you pay for 1 kW of electricity.

There is no standard price for electricity cost per kWh in the UK, so to find this amount, look on your energy bill.

It’s worth noting if you are on a default tariff and subject to the price cap, then your supplier can currently charge up to 28p per kWh.

With this in mind, you’d take your 0.84kW, and times it by 28 – equalling 23.5p.

The equation is: cost = power (kilowatt) × time (hour) × cost of 1 kWh (pence).

So if your fan costs 23.5p to have on for that long, and you have it on for a full week, that adds up to £1.64.

If you had it on every day for that length of time over a month, that would be £7.28.

Of course, costs will vary depending on the type of fan you have, how long you’re using it for and how much your energy costs.

Do fans make a room cooler?

Although fans can’t make a room cooler, they can make you feel cooler.

The air moving over your skin can lower your body temperature but won’t do much about the heat inside a room.

So if you don’t plan on being in the room there’s no point of leaving the fan on as it won’t do anything to the heat inside the room itself.

How else can I keep cool in the heat?

Relying on just a fan to keep you cool could be adding to bills during a heatwave, but there are other options you could try.

You could try cooling your sheets down before bed by sticking them in the freezer, according to TikTok star That Property Guy.

Shutting curtains and blinds during the day can help the house stay cool, while opening the windows on both sides of your home can create a cooling through-breeze without the cost.

He also recommends avoiding using the oven and turning off appliances which are not in use as they kick off heat too, even on standby.

Tom Church, Co-Founder of, said that having a cool shower before bed can set you up for the night to avoid overheating.

You could try putting hot water bottles in the freezer, or a plastic bottle if you don’t have one.

You could also make your fan work harder by putting a a bowl of with water and ice in front to cool down the house.

We have also calculated how much it costs to leave your air conditioner on all night.

It’s not just us struggling in the heat, here’s eight gadgets to keep cool in a heatwave – including your furry friends.