Running air conditioning in Australia costs roughly 20 cents to $4 per hour, depending on the size of the unit and what you pay for electricity. A small split system cooling one room costs about 20 to 40 cents per hour. A large ducted system heating or cooling a whole house can cost $2 to $4 per hour. The biggest factor is how much electricity your unit actually draws each hour, which is usually far less than its kW rating suggests.
At QuickAir, we’ve serviced and installed heating and cooling in more than 20,000 Australian homes, and “what does it cost to run?” is one of the questions our technicians hear most on site. The math is simple once you know two numbers: the power your unit draws and your electricity rate. Below we break down the running cost per hour by system size and by state, explain what pushes the number up, and show the simplest ways to bring it down.
How to work out your air conditioner’s running cost per hour
Your running cost per hour comes down to one sum:
Running cost per hour = power the unit draws (kW) x your electricity rate (dollars per kWh)
For example, a unit that draws 1 kW of power, running for one hour at a rate of 35 cents per kWh, costs about 35 cents to run. Run that same unit for eight hours and you’re looking at around $2.80 for the day.
Capacity and power draw are not the same number
This is where most online calculators get it wrong. The kW figure on the box, like 3.5 kW, is almost always the cooling or heating output, not the electricity the unit uses. A reverse cycle air conditioner moves heat rather than making it, so it draws far less power than it delivers. A typical 3.5 kW split system draws roughly 1 kW of electricity while it’s running. Always use the power the unit draws, not its capacity, or you’ll badly overestimate the cost. If you’re not sure of your unit’s power draw, it’s listed on the compliance plate on the indoor or outdoor unit, or in the manual under “rated input” or “power input.”
Cost to run air conditioning per hour by system size
The table below shows the typical running cost per hour for common system types, based on the power each one draws and an electricity rate of 30 to 40 cents per kWh, which covers most of the country. Treat these as a guide, because the exact cost depends on your unit’s efficiency and how hard it’s working.
| System type | Power drawn (kW) | Cost per hour at 30c/kWh | Cost per hour at 40c/kWh |
| Small split, one room | 0.5 to 1.0 | 15c to 30c | 20c to 40c |
| Medium split, living area | 1.2 to 1.8 | 35c to 55c | 50c to 70c |
| Large or multi-head split | 2.0 to 2.5 | 60c to 75c | 80c to $1.00 |
| Ducted system, running several zones | 4.0 to 8.0 | $1.20 to $2.40 | $1.60 to $3.20 |
| Ducted system, full load | up to 10 | up to $3.00 | up to $4.00 |
The pattern is clear. A single split cooling one room is cheap to run, often less than the cost of a couple of light globes. A ducted system conditioning the whole house uses far more power, because it’s doing far more work. Most of the time you land somewhere in between, since few systems run flat out for long once the room reaches temperature.
How much does it cost to run a split system per hour?
A split system costs about 20 cents to $1 per hour to run, which makes it the cheapest way to cool or heat the rooms you actually use. A small bedroom unit sits at the bottom of that range, while a large unit heating or cooling an open-plan living area sits near the top. Because a split system only conditions the room it’s in, you’re not paying to cool empty bedrooms or hallways. Modern reverse cycle splits are also inverter driven, so once the room hits the set temperature the unit eases back and draws less power, rather than switching fully on and off.
How much does it cost to run ducted air conditioning per hour?
Ducted air conditioning costs about $2 to $4 per hour to run when it’s conditioning the whole home. That’s more than a split, because a ducted reverse cycle system pushes conditioned air through every room from one large unit. The upside is whole-home comfort from a single system that both heats and cools. You can bring the cost down by zoning, which lets you shut off air to rooms nobody is using, so you’re not paying to condition the whole house when you only need the living area.
How your state changes the cost
Electricity prices vary widely across Australia, so the same air conditioner costs more to run in some states than others. Household rates sit between 24 and 45 cents per kWh depending on your state and network, according to Canstar figures updated in May 2026. The table below shows what one hour costs for a typical split system drawing 1 kW of power.
| State (main network) | Typical rate per kWh | Cost per hour for a 1 kW split |
| Victoria | around 27c | around 27c |
| Tasmania | around 28c | around 28c |
| Australian Capital Territory | around 31c | around 31c |
| Queensland | around 33c | around 33c |
| New South Wales | 36c to 40c | 36c to 40c |
| South Australia | around 44c | around 44c |
A household in South Australia can pay well over half as much again as one in Victoria to run the same unit for the same hour. If your rate is at the higher end, efficiency and sensible use matter that much more.
What affects how much your air conditioner costs to run
Two identical-looking units can cost very different amounts to run. These are the factors that make the biggest difference.
- Power draw and system size. A bigger, higher-capacity unit draws more power. A single split is cheap, a whole-home ducted system is not.
- Your electricity rate. The same unit costs more per hour in a high-tariff state like South Australia than in Victoria. Time-of-use tariffs also mean running the system in the late afternoon and evening peak can cost more than during the day.
- The temperature you set. The harder you ask the unit to work against the outside temperature, the more power it draws. Setting 18 degrees on a hot day costs far more than 24.
- Insulation and the home itself. A poorly insulated house with gaps around doors and windows loses conditioned air constantly, so the unit runs longer to hold the temperature.
- Efficiency and star rating. A high-star inverter model draws less power for the same output. An older, single-speed unit works harder and costs more per hour.
- Servicing and condition. Blocked filters, dirty coils, and low refrigerant all make a unit work harder and draw more power for less cooling.
- Climate and humidity. In humid conditions the unit spends energy removing moisture as well as heat, which lifts the running cost.
How to reduce your air conditioning running costs
The running cost is largely in your hands once the unit is installed. A few habits make a real difference.
- Ease off the thermostat. The Australian Government notes you can save up to 10% on running costs for each degree you adjust, warmer in summer and cooler in winter. Set 24 to 25 degrees in summer rather than 18, and the unit draws noticeably less power.
- Only cool the rooms you use. Close doors to unused rooms, or use zoning on a ducted system, so you’re not paying to condition space nobody is in.
- Seal the room. Shut windows and external doors, and close blinds against the afternoon sun. Every bit of heat you keep out is heat the unit doesn’t have to remove.
- Keep it serviced. A clean, well-charged system reaches temperature faster and draws less power. A neglected one quietly costs you more every hour it runs.
- Choose the right size and efficiency when you replace. An oversized or low-efficiency unit costs more to run for its whole life. Matching the system to the room and choosing a high-star inverter model keeps the running cost down from day one, which is worth factoring in at installation.
Does servicing your air conditioner reduce running costs?
Yes. A dirty or poorly maintained system draws more power for less cooling, so it costs more every hour it runs. Filters clogged with dust restrict airflow, dirty coils make the unit work harder to shift heat, and low refrigerant means it never quite reaches temperature. We see it on service calls regularly: a unit that has quietly cost its owner more every summer for years, simply because the filters and coils were never cleaned. We recommend a service every year, or every two years at a minimum, to keep a system running at its rated efficiency. You can see what a service and maintenance visit covers, from cleaning filters and coils to checking the refrigerant charge and the compressor’s power draw.
Frequently asked questions
How much does it cost to run air conditioning for 24 hours?
A typical split system running non-stop for 24 hours costs roughly $5 to $10 in electricity, based on a 0.7 to 1 kW draw at 30 to 40 cents per kWh. A ducted system conditioning the whole home can add $20 to $50 to a day’s power use if it runs much of the day. In practice most units cost less than this, because once the room reaches temperature an inverter unit eases back rather than running at full power.
Is it cheaper to leave the air conditioner on all day or turn it off?
For short absences of an hour or two, leaving an inverter split running at a steady temperature can be cheaper than letting the house heat up and then cooling it back down from scratch. For longer absences, turning it off saves more. The most expensive thing you can do is run it hard against a wide temperature gap, so a steady, sensible setting usually beats blasting it cold on and off.
Does air conditioning use a lot of electricity?
A single split system does not. At 20 to 40 cents per hour it’s one of the cheaper appliances in the house to run for the comfort it gives. Whole-home ducted air conditioning uses considerably more, which is why it lands at $2 to $4 per hour. The total on your bill depends far more on how many hours you run it than on the unit itself.
What temperature should I set my air conditioner to in summer?
Around 24 to 25 degrees is the sweet spot for summer cooling in most Australian homes. It’s comfortable, and it keeps the gap between inside and outside small enough that the unit doesn’t have to work hard. Every degree cooler than that can add up to 10% to your running cost.
Is reverse cycle air conditioning cheaper to run than a gas heater?
In most cases, yes. Reverse cycle air conditioning is one of the most efficient ways to heat a room, because it moves heat rather than generating it, so it delivers more warmth per dollar than most gas heating. It also cools in summer from the same unit, which a gas heater cannot do.
Keep your running costs down with a well-maintained system
The cheapest air conditioner to run is one that’s the right size for the room and kept in good condition. If yours is struggling to reach temperature, running longer than it used to, or you suspect it’s costing more than it should, a service is the quickest way to get it back to its rated efficiency. Our licensed technicians work across every capital city, most bookings same day or next morning, with fixed pricing you know before we arrive and a 100% workmanship guarantee on every job. Get in touch or call us on 1300 730 896.
