How much does it cost to run a fan in the UK? How much electricity fans use and cost of running one overnight

The UK is basking in an unexpected autumnal heatwave, with temperatures going as high as 32°C in some areas.

September’s Indian summer is expected to last for at least several more days. It comes after a largely disappointing summer, which saw rain and cool temperatures dominate the weather.

It all comes as the UK grapples with its worst cost of living crisis in a generation. Most households have seen their spending power drop in the face of record headline inflation and soaring interest rates.

Energy bills have been one of the drivers of the crisis. While they are set to go down again at the end of the month when the new Ofgem energy price cap kicks in, they remain well above the rates people were paying before the Covid-19 pandemic hit the UK. It means you may well be using power more sparingly than before.

But, in light of the hot weather, how much does it cost to run a fan - and how can you work out how much electricity it will use?

How much does it cost to run a fan?

The amount of electricity a fan uses depends on what type of model you have, as well as the levels of power needed at its different settings. Small fans are likely to use around five watts, while bigger ones could eat up as much as 100 watts. So, you must first find out how much energy your fan uses to be able to predict how much it will cost to run.

Say you have a fan whose highest setting is 80 watts - you’ll need to work out what this equates to in kilowatt hours (kWh) (i.e. the number of kilowatts used over 60 minutes - the standard metric for energy pricing in the UK).

To do this, you must divide the wattage by 1,000. This will leave you with how many kilowatts-per-hour your fan is burning up. In the case of our 80-watt fan, this figure would be 0.08 if you always use it on its highest setting.

You then want to multiply this figure by how many hours you’re using the fan for. If it’s two hours, it will be 0.16kWh - if it’s nine hours because you’re using it overnight, the figure will be 0.72kWh.

Now you know the maximum amount of power you will be using, you will need to find out how much you pay for each unit of electricity and then multiply the kWh figure with it. Under the current Ofgem energy price cap, which is due to remain as the maximum bills limit for people on standard variable tariffs until the end of September, a unit comes to an average price of 30p with a 53p daily standing charge. When the new Ofgem limit kicks in from 1 October, unit prices will fall to 0.27p with the 53p daily standing charge remaining the same. You’ll want to multiply these unit prices with the amount of energy your fan has used.

Say your 80-watt fan has run overnight for nine hours this week, it will have cost you 21.6p - or just over 2p an hour. Your daily standing charge, which applies to all of your energy usage and is therefore spread across all of your appliances and devices, means you will pay slightly more for your fan in real-terms.

In the unlikely event it remains uncomfortably warm into October, the cost of running your fan overnight will come in at 19.4p. Under current projections, it is likely unit prices will remain around their current level well into 2024, so this usage cost may not change all that much for next summer.