AC Running Cost Calculator

Work out ac running cost instantly with clear inputs, formula shown and shareable results.

About AC Running Cost Calculator

An air conditioner's electrical draw is its cooling output divided by the coefficient of performance, so a 3.5 kW unit at COP 3.8 consumes only 0.92 kW. That is why COP or SEER matters far more than headline capacity for running cost.

Formula

AC running cost

power = cooling capacity / COP; cost = power x hours x tariff

Worked example

With the default values below, AC Running Cost Calculator returns Daily running cost of $1.55. Change any input above and every figure here is recalculated in your browser.

Inputs used

Cooling capacity: 3.5 kW
Coefficient of performance: 3.8 COP
Running hours per day: 6 h/day
Electricity rate: 0.28

Results

Daily running cost: $1.55
Monthly cost: $47.10
Electrical power draw: 0.92 kW
Cost over a 120 day season: $185.68

Step by step

1Values used
2AC running cost
3Daily running cost= 1.55
4Monthly cost= 47.10
5Electrical power draw= 0.92 kW
6Cost over a 120 day season= 185.68

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

What is a good COP?

3.5-4.5 for a modern inverter split unit at rated conditions. Seasonal figures (SEER or SCOP) are lower and more representative of real use.

Does a higher thermostat setting save much?

Yes. Each degree of setpoint raise typically cuts consumption by 3-8%, because the temperature difference driving the heat load falls.