Air Conditioner Running Cost Calculator Australia
Work out what your split, ducted, window or portable air conditioner actually costs to run per hour, per day and over a cooling or heating season, using your own electricity rate.
No government or average rate is built in. You enter your own electricity rate from your bill. This calculator does not assume a national, state or retailer default rate for you.
Enter Your Air Conditioner Details
Input power is what the unit draws from the wall. It is on the compliance plate, usually on the outdoor unit, and is not the same as cooling capacity.
Check the compliance plate or the unit's spec sheet for "rated input" or "power input" in kW.
This sets an illustrative input power as a share of cooling capacity, not an official figure. Use your own compliance plate reading whenever you can for a more accurate result.
An inverter unit draws close to its full input power while pulling a room down to temperature, then throttles back once it holds. 65% is a reasonable middle setting for a room that is already fairly close to the set temperature. Move it up toward 90 to 100% for a hot afternoon with doors open, or down toward 30 to 40% for overnight in a small, closed room.
Use the usage rate on your own electricity bill, not a general figure you have seen somewhere else. If you are on a time of use plan, use the rate that applies when you usually run the unit.
Use this if you are adding up more than one split system, or multiple ducted zones running together.
Estimated running cost
This is an estimate built only from the input power, duty cycle, hours and rate you entered. Real running costs shift with outdoor temperature, insulation, room size, thermostat setting and how often doors are opened.
How Much Does It Cost to Run an Air Conditioner in Australia
Air conditioning is one of the biggest single swings in an Australian power bill, and it is also one of the few appliance costs most people can estimate properly before they commit to running it through a long hot stretch or a cold snap. The maths is simple once you know the right number to start from: the unit's input power, not its cooling capacity, multiplied by your electricity rate, adjusted for how hard the compressor is actually working. This calculator does that for split systems, ducted systems, window units and portable units, using only the rate from your own bill.
Input Power Versus Cooling Capacity: The Number That Actually Costs You Money
Air conditioners in Australia are usually sold and labelled by their cooling or heating capacity in kW, since that is the figure that tells you whether a unit will cool a given room size. A "5kW split" or a "7kW split" refers to the output, the amount of heat the unit can move. The running cost, though, depends on input power, which is what the unit actually draws from the wall to produce that output.
For a reasonably efficient inverter split system, input power typically sits somewhere between a quarter and a half of the cooling capacity figure. A 5kW split, for example, might draw somewhere around 1.3 to 1.6kW at full load. The exact number is on the compliance plate, usually fixed to the outdoor unit, or in the product's technical specification sheet. If you can find that figure, use it directly in this calculator rather than estimating from capacity, since it removes a layer of guesswork.
Why Your Air Conditioner Does Not Draw Full Power the Whole Time
Almost every split and ducted system sold in Australia today is an inverter unit. Unlike an older fixed speed unit that cycles fully on and fully off, an inverter ramps up hard to pull a room down to the set temperature, then throttles back and runs at a much lower power draw to simply hold that temperature. That is why a unit rated at 1.5kW input power does not use 1.5kW for every minute it is switched on.
This calculator handles that with a duty cycle setting. A higher duty cycle, closer to full load, suits a hot afternoon with the doors open or a room that has been sitting closed up all day. A lower duty cycle suits overnight use in a smaller, well sealed room once the temperature has already settled. Moving that one slider can change the estimated cost more than almost any other input, so it is worth adjusting it to match how you actually use the unit rather than leaving it on a single default.
Split, Ducted, Window and Portable: Why the Type Matters
A split system conditions one room or a small zone and is generally the cheapest option to run for that single space, because there is less air to move and less duct loss. A ducted system conditions a much larger area, often the whole house, and draws a correspondingly higher input power, but can be efficient per square metre when it is properly zoned so you are not cooling or heating rooms nobody is using. A window or portable unit is usually the least efficient per kW of cooling, since the design trades some efficiency for flexibility and lower upfront cost. None of these are automatically the cheapest choice for every household; it depends on how much space you actually need conditioned and for how long.
Worked Example
These numbers are illustrative only, to show the method:
| Item | Figure |
|---|---|
| Input power | 1.5 kW |
| Duty cycle | 65% |
| Average draw | 1.5 × 0.65 = 0.975 kW |
| Electricity rate | 30 c/kWh |
| Cost per hour | 0.975 kW × $0.30 = about $0.29 |
| Running 6 hours a day for 90 days | about $158.00 |
Change the duty cycle to 90% for a scorching run of days and the same unit costs closer to $0.41 an hour, which shows how much that single setting matters compared with the headline input power figure.
Reducing Air Conditioner Running Costs Without Buying a New Unit
- Set a sensible target temperature. Each extra degree of cooling, or heating, pushes the compressor harder and lifts the duty cycle.
- Close doors and curtains. Less heat coming in during summer, or escaping in winter, means the unit spends more time at the lower, efficient end of its duty cycle.
- Use zoning properly on ducted systems. Conditioning only the rooms in use rather than the whole house at once is one of the simplest savings available.
- Clean or replace filters regularly. A clogged filter forces the unit to work harder for the same result, which quietly raises the effective duty cycle over time.
- Check your electricity rate, not just your usage. If a large share of your air conditioning happens during an expensive time of use window, moving some of that use, where practical, can matter as much as cutting hours.
Checking the Rest of Your Bill
Air conditioning rarely explains a whole quarter's bill on its own. If your bill came in noticeably higher than expected, the electricity bill increase calculator compares two bills side by side and splits the change into usage, rate, supply charge and other causes, which is a useful next step once you know what your air conditioner itself is contributing.
Frequently Asked Questions
How much does it cost to run an air conditioner per hour in Australia?
Multiply the unit's input power in kW by your electricity rate in dollars per kWh, then adjust for how much of the hour the compressor actually runs. A 5kW split drawing around 1.5kW at 30c/kWh costs roughly 45 cents an hour at full load, and less once it reaches temperature and cycles down.
What is the difference between cooling capacity and input power?
Cooling capacity is the output, how much heat the unit removes from a room, measured in kW. Input power is what the unit draws from the wall to do that, also in kW. Running cost depends on input power, not cooling capacity, and input power is usually a third to a half of the capacity figure.
Why does my air conditioner use less power once the room is cool?
Most Australian split and ducted systems are inverter units. Once the room reaches the set temperature, the compressor throttles back instead of switching fully on and off, so the average power draw over an hour is lower than the unit's maximum input power.
Is ducted air conditioning more expensive to run than a split system?
Usually yes for the whole house, because ducted systems condition more floor area and draw more input power. Per square metre cooled, a well zoned ducted system and an efficient split system can be closer in cost than the headline input power suggests.
Does a higher star rating always mean a cheaper air conditioner to run?
A higher star rating generally means better efficiency for a given capacity, but star ratings are not directly comparable across different capacity units. Two units with the same stars but different capacities can have very different running costs.
How much does it cost to run air conditioning all summer in Australia?
It depends on the unit's input power, how many hours a day it runs, how often it cycles down and your electricity rate. This calculator works it out from your own figures rather than a single national average, since usage and rates vary a lot between households.
Does this calculator use a government or average electricity rate?
No. You enter your own electricity rate from your bill. The calculator does not fill in any default, government or state average rate.
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