How much does an air conditioner cost to run?
Estimate cooling-energy cost using electrical input power. Do not use cooling capacity in BTU/h or kW unless the specification explicitly identifies it as electrical input.
How this calculator works
Air conditioning is unusual among household appliances because the number on the box rarely matches what the unit actually draws. EuroWattCalc takes the electrical input power you enter, converts it from watts to kilowatts, multiplies by the hours and days you specify, then applies your electricity price to the result.
What can change the real cost?
- Inverter air conditioners can modulate power after the room approaches its set temperature, so maximum input may overstate average draw.
- Outdoor temperature, insulation, sun exposure, room size and thermostat setting affect load.
- Filters and airflow can affect system performance; follow the manufacturer's maintenance instructions.
Air-conditioning specifications can contain several different power figures, so choosing the electrical input is the most important step.
Frequently asked questions
Can I enter the cooling capacity shown in kW?
Only if it is specifically electrical input. A unit may have several kilowatts of cooling capacity while consuming much less electrical power.
Why does inverter AC power vary?
An inverter can change compressor speed to match the cooling load instead of operating only at full output or off.
Does this calculate heating mode too?
It can estimate electrical running cost if you enter the actual electrical input for heating operation.
Typical air conditioner running costs
Air conditioning is a fast-growing electricity cost across southern and central Europe as summers lengthen, and it is also one of the appliances where nameplate wattage can mislead people the most. Inverter-driven units modulate compressor speed continuously, so the number on the specification sheet is a maximum rather than a typical draw. Estimating cost from an average or observed wattage — rather than the highest figure quoted in marketing material — gives a far more realistic monthly total, especially for units that spend most of their time maintaining rather than reaching a target temperature.
| Scenario | Power | Use | Approx. cost* |
|---|---|---|---|
| Portable AC unit (small room) | 900–1,200 W | 4 h/day | €0.11–€0.14 |
| Split-system AC (medium room) | 1,500 W | 6 h/day | €0.27 |
| Central / larger split system | 2,500–3,500 W | 6 h/day | €0.45–€0.63 |
| Peak summer month, 6 h/day at 1,500 W | 1,500 W | 6 h × 30 days | ≈€8.10 |
*Estimated at €0.30/kWh usage price. Your own tariff, appliance model and habits will change the real figure — use the calculator above with your own numbers.
More frequently asked questions
Does the energy rating (A+++ etc.) change what I enter?
Yes indirectly. A higher-efficiency unit will typically draw less power for the same cooling output, so check the unit's actual rated wattage rather than assuming all air conditioners of a similar cooling capacity use the same electricity.
Why does my AC use less than its maximum wattage most of the time?
Most modern units are inverter-driven and modulate their compressor speed once a room reaches the target temperature, so average draw is often well below the maximum rated wattage on the nameplate.
