GBP, USD, CAD and AUD
Portable air conditioner running cost.
Use electrical input power, your own unit rate and the hours you really expect to run it. No hard-coded “current tariff” and no email required.
2
Example result — add your tariffElectricity use only. Purchase and maintenance are excluded.
Step 2 of 2Estimated monthly electricity cost
£36.0020 days at 6 hours per day1.20 kWh for each full-power hourUse measured input power when possible
The rated cooling capacity in kW is not the same as electrical input power. Read the input-power figure on the label or manual. Thermostat cycling, fan-only periods, hose setup, outdoor heat and room leakage change actual consumption.
How the calculation works
Electrical input in kilowatts × time × your unit rate.
Watts are divided by 1,000 to get kilowatts. Kilowatts × hours gives kWh; kWh × your unit rate gives the additional electricity cost. Monthly cost multiplies the daily result by the number of use days you enter, and seasonal cost multiplies that by your chosen cooling months.
The model assumes the entered electrical power is drawn for every operating hour. That makes the result easy to audit and often conservative when a thermostat cycles the compressor.
What changes the result
Factors worth checking before you decide.
Electrical input power—not advertised cooling output.
Your actual tariff and whether it changes by time of day.
Thermostat and compressor cycling after the room cools.
Outdoor temperature, solar gain and air leaking around the exhaust hose.
Target temperature, fan speed and room size.
A single-hose portable unit can draw warm replacement air into the room.
Worked examples
See how the assumptions move the answer.
Four hours on each day would add £1.00 before any compressor cycling.
Multiply 7.2 by your price per kWh to get the daily electricity cost.
The seasonal estimate uses only the number of days and months you enter.
Common questions
Questions homeowners ask before spending.
How much does a portable air conditioner cost to run per hour?
Divide the electrical input watts by 1,000, then multiply by your electricity unit rate per kWh. For example, 1,200 W is 1.2 kW, so one full-power hour uses about 1.2 kWh.
Is cooling capacity the same as electrical input power?
No. A product may advertise cooling capacity in BTU/h or kW while drawing a different number of electrical watts. Use the input-power figure from the rating label or manual.
Why might my measured cost be lower than the calculator?
The compressor may cycle off after the target temperature is reached, leaving only the fan running. The calculator treats entered watts as continuous while the unit is on, so use a plug-level energy meter for a measured session.
Does this include the standing charge?
No. The standing charge is paid regardless of whether the air conditioner runs. This calculator estimates the additional unit-rate cost attributable to the appliance.
Can I use dollars or Canadian and Australian dollars?
Yes. Select the country and enter the electricity rate in cents per kWh. The formula does not assume a national tariff.
Sources and review trail
Transparent inputs, versioned model.
- Last reviewed
- 13 September 2026
- Model/version
- appliance-cost-2026.09.1