EnergyCostHub guide
How Much Does Air Conditioning Cost to Run in the UK?
Estimate the electricity cost of running portable or split air conditioning in the UK from the unit's input power, your use pattern, and your current tariff.
The useful running-cost calculation is electricity input power in kW multiplied by hours per day, days used, and your electricity unit rate. For example, a unit drawing 0.9 kW for six hours a day over 30 days uses about 162 kWh. At Ofgem's average Direct Debit electricity unit rate of 26.11p/kWh for 1 July to 30 September 2026, that usage costs about £42.30 before considering any change to the home's existing standing charge. The unit rate is the important variable because a standing charge is normally paid whether or not the air conditioner is used.
Do not use cooling capacity as if it were electricity use. A label such as 2.5 kW can describe how much heat the appliance can move, while the input power is the electricity drawn to do that work. Check the product label, technical sheet, or measured plug-in energy use for input power. Cooling demand changes with outdoor heat, sun through glazing, room size, insulation, thermostat setting, humidity, and how often doors or windows are opened, so the appliance may not draw the same amount all day.
A portable air conditioner can be a practical short-term option for one room, but the exhaust hose and window opening affect performance. A fixed split system may cool more effectively across repeated hot periods, yet its running cost still depends on the actual input, controls, and tariff rather than the headline model name. Compare like-for-like scenarios: the same room, operating hours, temperature setting, and electricity rate. That makes the difference between equipment options easier to understand without treating either calculation as a guarantee.
Use the UK Energy Bill Calculator to add the estimated air-conditioning kWh to a typical billing period and replace the default tariff with the rate on your bill. Smart-meter or interval data can help show whether cooling use overlaps with higher-priced time-of-use periods. If your tariff has peak, off-peak, or fixed-term pricing, use the applicable rate instead of the national average. Record the date and tariff type, because Ofgem's cap and supplier prices can change.
This guide estimates electricity use only. It does not quote equipment prices, installation work, technical suitability, planning permission, landlord consent, or a safe electrical design. If cooling is needed for a heat-sensitive person, follow relevant health advice as well as cost guidance. Before choosing fixed equipment, compare the scope, noise information, warranty, refrigerant work, and electrical work included in written installer proposals.
For a useful comparison, keep the period, units, and assumptions consistent across each option. Use a calculator to explore the figures, then rely on current documents from the relevant provider or authority for terms that apply to your home.
What to check next
Use the related calculator or guide to compare the assumptions that matter for your home, then confirm any tariff, quote, or program term with the relevant provider or authority.