Choosing a new split system? Text us the room and how you use it, and we’ll suggest a size. Our automated quote assistant replies straight away, at any hour.
To work out an air conditioner’s running cost, multiply the electricity it uses, in kWh, by the usage rate on your power bill. The kWh comes from the system’s power input and the hours it runs, or from the yearly figure on its Energy Rating label. The 2.5 kW or 5 kW on the box is cooling output, not the electricity it uses.
The quick answer
- Running cost = energy used in kWh × your tariff in dollars per kWh.
- Energy used in kWh = power input in kW × hours of use.
- The Energy Rating label shows each model’s estimated energy use in kWh a year, for hot, average and cold climate zones.
- The Australian Government says each extra degree of cooling in summer adds 5% to 10% to your energy use.
The three figures you need
You need three things before you do any sums. Write them down first.
| Figure | Where to find it |
|---|---|
| Power input, in kW | The rating plate on the unit, or the product sheet. If it’s in watts, divide by 1,000. |
| Hours of use | How long the system runs on a typical day. |
| Your tariff, in dollars per kWh | Your electricity bill. Energy Rating says it’s in the service calculation section. |
Don’t use the cooling capacity. A 5 kW split system doesn’t draw 5 kW from the wall. The capacity is the heat it moves out of the room, and the power input is the electricity it uses to do that.
If you’re on a time of use plan, the rate changes during the day. Note which rate applies to the hours you run the system.
How do I calculate air conditioner running cost?
Do it in two steps. First work out the energy in kWh, then multiply it by your tariff.
- EnergyPower input (P, in kW) × hours of use (H) = energy used (E, in kWh).
- CostEnergy used (E) × your tariff (T, in dollars per kWh) = running cost for that period.
- Scale upMultiply the daily figure by the number of days you use it in a month or a summer.
For example, a system with a power input of 1.2 kW that runs for 6 hours uses 7.2 kWh. Multiply 7.2 by the rate on your bill, and that’s the cost of that day’s cooling at full input.
That’s a high estimate. An inverter system slows its compressor once the room reaches the set temperature, so it rarely draws full input for every hour it runs.
Use the Energy Rating label for a yearly figure
The Zoned Energy Rating Label must be shown on air conditioners for sale in stores. It gives the estimated annual energy use in kWh, with cooling in blue and heating in red, for three climate zones.
The label sum, from Energy Rating
Annual running cost = total energy use for cooling and heating, in kWh, from the label × your tariff in dollars per kWh.
The label assumes set hours of use. For the hot climate zone, it’s 2,247 hours a year of cooling and 277 hours of heating. If you run the system for fewer hours than that, your cost will be lower than the label sum.
The Energy Rating Calculator tells you which zone your postcode is in, and lets you compare models side by side.
What makes the real figure higher or lower
The sum gives you a starting point. How you use the system, and the room it’s in, move the real figure up or down.
| Factor | Effect |
|---|---|
| Set temperature | Each extra degree of cooling in summer adds 5% to 10% to energy use, according to energy.gov.au. |
| System size | Of two correctly sized systems with the same star rating, Energy Rating says the larger one uses more electricity. |
| Insulation and shade | Heat coming in through the ceiling or sunny windows makes the system work harder. |
| Dirty filters | Blocked filters cut airflow, so the system runs longer to cool the room. |
| Time of day | On a time of use plan, the same kWh costs more at the peak rate. |
The star rating compares models of a similar size. More stars means a more efficient system, so choose the size first and then compare stars between models of that size.
Text for a quote Call 07 4428 2766
How to bring the running cost down
Most of the savings come from how you use the system. The Australian Government’s heating and cooling advice lists these.
- Set the thermostat a degree or two warmer in summer.
- Switch the system off before you leave the house or go to bed.
- Keep the indoor unit dust free, and wipe the vents, filters and louvres without harsh cleaners.
- Book a service before the hot months, in late spring.
- Improve insulation, draught sealing and shading around the home.
Our split system service and clean is $341 including GST for one unit. Our air conditioning service Brisbane page shows what it covers.
Leave the inside of the system alone. Don’t remove covers, touch the wiring or try to add refrigerant. A breaker that keeps tripping needs a licensed electrician to find the cause.
Comparing systems before you buy
Get the size right first. A system that’s too small runs flat out more often, and one that’s too big short cycles. Our guide to what size air conditioner you need has a room size chart.
Then compare the label’s annual kWh between models of that size, for your climate zone. We supply and install Haier, Mitsubishi Heavy Industries and Daikin split systems, under ARCtick licence L181564 and QLD Electrical Contractor Licence 90552.
| Split system | Price including GST |
|---|---|
| 2.5 kW | from $1,814.51 |
| 3.5 kW | from $2,014.50 |
| 5.0 kW | from $2,414.50 |
| 7.1 kW | from $2,814.50 |
| 8 to 9.5 kW | from $3,761.25 |
Each price is for one system installed back to back on a single storey home. Every size and brand is on our air conditioning prices in Brisbane page, and our air conditioner installation Brisbane page covers the installation itself.
Common questions about air conditioner running cost
Is reverse cycle heating counted on the label?
Yes. The label shows heating energy use in red, beside cooling in blue. The label sum uses the total of both.
Why isn’t the label figure on my bill?
The label is measured under standard test conditions with set hours. Your hours, set temperature, room and tariff will be different, and your bill includes every other appliance and the daily supply charge.
Is there a calculator for this?
Yes. The Energy Rating Calculator compares labelled models by postcode, and our running cost calculator guide walks through the sums.
Our advice
Use the power input, your hours and the rate on your bill to get a running cost you can trust. When you’re buying, pick the size first, then compare the label’s yearly kWh between models of that size, and keep the filters clean once it’s in.
Get a fixed price for an efficient split system
Text us the room and how you use it. Our automated quote assistant replies straight away, at any hour.
Text for a quote Call 07 4428 2766
Calls are answered Monday to Friday, 7am to 3:30pm. Or send the details online.
Prices current as of 5 October 2026 and include GST. Running costs are not Faze prices: they depend on your tariff. Sources: Energy Rating, “Understand the Zoned Energy Rating Label”; Australian Government, energy.gov.au, “Heating and cooling”. This article is general information. It is not advice about your system.
Related guides
How to Prevent Air Conditioner Short Cycling
Air Conditioner Replacement Cost Brisbane: 7 Key Factors
Do You Need a Licensed Electrician to Install an Air Conditioner in QLD?- Why Is My Air Conditioner Not Cooling? Brisbane Troubleshooting Guide
- Air Conditioner Warranty in Australia: What to Know
All guides: electrical and air conditioning guides.
Licensed electricians and ARCtick refrigeration technicians, Queensland Electrical Contractor Licence 90552 and ARCtick L181564. We install and service split systems and do the electrical across Logan, Brisbane southside, Ipswich and the northern Gold Coast.
About Faze | Call 07 4428 2766 | Text 0489 275 747