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How much does it cost to run a portable air conditioner?

A portable air conditioner costs about 21p an hour to run.

Based on the Ofgem price cap rate of 26.32p per kWh. Price cap period 1 Oct 2026 to 31 Dec 2026. By Andrew Chambi, energy consultant (OCDEA, CIBSE LCC and LCEA). Last reviewed 28 October 2026.

Work out your cost

-per day
-per week
-per month
-per year

Find the wattage on the label or rating plate, usually on the back or underneath.

Low, typical and high running costs

Using 4 hours a day.

RatingUnit costPer weekPer year
Low780W16p / hour£4.60£239.79
Typical990W21p / hour£5.84£304.34
High1,600W34p / hour£9.43£491.87

How it compares

ApplianceTypical usePer dayPer month
Storage heater7 hours a day£2.14£65.15
Hot tubswitched on all day£2.11£64.05
Oil-filled radiator4 hours a day£1.47£44.83
Fan heater3 hours a day£1.26£38.43
Portable air conditioner4 hours a day83p£25.36
Electric fan6 hours a day6p£1.92

How we work it out

Cost per hour = watts ÷ 1,000 × share of time at full power × price per kWh. For a 990W portable air conditioner at 80%: 990 ÷ 1,000 × 0.8 × 26.32p = 21p. A thermostat switches the element on and off, so it doesn't draw full power the whole time. The 80% figure is our assumption. It depends on the room, the weather and the thermostat setting, so change it in the calculator if you know better.

The low, typical and high figures are for models sold in the UK, taken from the sources below. Your own appliance may differ, so check its rating plate or energy label for the most accurate figure.

Sources

Questions

How much electricity does a portable air conditioner use?

Most use between 780W and 1,600W. A 990W model running at full power uses 0.99 kWh an hour.

How much does a portable air conditioner cost to run per day?

Used for 4 hours a day it costs about 83p, based on the Ofgem price cap rate of 26.32p per kWh.

Where does the electricity price come from?

We use the Ofgem price cap average for Great Britain, paying by Direct Debit: 26.32p per kWh for 1 Oct 2026 to 31 Dec 2026. Electricity rate includes 0% VAT, which applies from 1 October 2026 to 31 March 2027. Storage heater and EV pages use an off-peak rate instead. Your own tariff may be higher or lower, so check your bill and enter your rate in the calculator.

See running costs for 40 appliances