Should I use p/kWh in this calculator?

Yes. Enter your electricity tariff in pence per kWh, such as 25 for 25p/kWh.

Are portable air conditioners expensive to run?

They can be. Portable units are often less efficient and may leak heat through the exhaust setup, so measured input watts are useful when available.

Calculator

AC Running Cost Calculator

Estimate AC kWh plus daily, monthly, and seasonal cost

UK air conditioning is usually a seasonal load, but heatwaves and home offices can make portable, window, and split systems visible on the bill. This calculator converts cooling capacity into input power using COP, then estimates daily, monthly, and cooling-season cost in pounds using your p/kWh tariff.

Enter Your Details

Start with the required inputs. Open advanced assumptions when you have a quote or utility details.

Fill in the form and click Calculate to see results.

Next best actions

Air conditioning cost is a seasonal load decision; compare it with whole-home use before changing solar or tariffs.

How to Use This Calculator

Choose the air conditioner type, enter cooling capacity in kW, then add daily runtime and your electricity tariff in p/kWh. Use the product energy label or datasheet for COP where available. Portable units often run less efficiently than fixed split systems, so check measured input power when you have it.

Formula & Methodology

Estimated input power = Cooling capacity (kW) / COP. Daily kWh = input power x daily runtime. Daily cost = daily kWh x tariff. Monthly cost multiplies by 30; season cost multiplies by entered cooling days. UK households should use their supplier tariff or Ofgem price-cap reference and treat AC as a seasonal load, not a year-round average.

Frequently Asked Questions

A 2.5 kW cooling unit at COP 3.0 running 5 hours uses about 4.2 kWh. At 25p/kWh, that costs about £1.04 per day.

Related Calculators

Energy ConsumptionCalculate household electricity usage from appliance wattage, runtime, and local rates.Solar ROI CalculatorEstimate your solar payback period, net savings, and return on investment over 25 years.Solar Panel SizingCalculate how many solar panels your home needs based on energy usage and roof space.Heat Pump Cost & SavingsEstimate heat pump install cost, annual heating cost, and savings vs gas, oil, propane, or electric resistance.