Air Conditioner Running Cost Calculator
Estimate what your air conditioner could cost per day, month and year using your own power rating, usage and electricity tariff.
Your estimate
Enter your values and select Calculate to see the estimate.
How the calculation works
The calculator uses a simple, transparent formula. When you know the electrical input power in kilowatts (kW), energy use is just power times runtime:
- Energy (kWh) = input power (kW) × hours run
- Cost = energy (kWh) × tariff (converted from c/kWh to A$/kWh)
If you only know the cooling capacity and an efficiency ratio (EER or COP), the estimated input power is capacity ÷ efficiency ratio. Tariffs are entered in cents per kWh and converted internally by dividing by 100.
- Input power vs cooling capacity
- Input power is the electricity the unit draws. Cooling capacity is how much cooling it delivers. A reverse-cycle unit with 7 kW cooling and a COP of 3 draws roughly 2.3 kW of electricity at full load.
Assumptions
Defaults in this tool are clearly labelled assumptions, not facts. In simple mode we assume the unit runs at its stated input power for the hours you enter. In advanced mode you can add a load factor (the compressor rarely draws full power the whole time), standby energy and weeks per year.
What this does not include
This estimate covers electricity to run the unit only. It does not include purchase, installation, servicing or repairs, and it does not model your exact thermostat behaviour, outdoor temperature, insulation or inverter modulation.
Worked examples
These are illustrative examples using labelled assumptions, not market claims. They are computed with the same formula as the calculator above:
- Small split system: 0.7 kW input, 6 hours/day, 30 c/kWh → about 4.2 kWh/day and approximately A$1.26/day while operating.
- Large ducted system: 3.5 kW input, 8 hours/day, 30 c/kWh → about 28 kWh/day and approximately A$8.40/day while operating.
How to improve the estimate
Read your unit's input power from the compliance plate or manual, use your actual usage tariff (check your bill), and in advanced mode set a load factor below 1 to reflect inverter modulation. Tariff is user-supplied, so this tool never assumes a national electricity rate.
Why a calculator, not a single number
How we calculated this
This estimate uses transparent inputs and a fixed formula. See our methodology for how ranges, sources and assumptions work.