What air conditioning actually costs to run
~20¢
per hour, typical bedroom split
It is on your bill. Most of Australia pays $0.25–$0.45.
Assumes a modern inverter delivering about 4 kW of cooling per kW of electricity, running at roughly 65% of rated output across the hour once the room is at temperature. Old non-inverter boxes and badly sized units cost more than this.
Bedroom / lounge split (3.5 kW)
$0.18/hour
Per day (6h)$1.09
Whole summer (90 days)$98
Winter heating (100 days)$109
Reverse cycle is the cheapest heating most Australian homes can buy — typically a third of the running cost of plug-in electric heaters for the same warmth.
Check my rebate and priceThe dirty secret of aircon running costs: the unit matters less than the settings.
Set 24 instead of 21 in summer and you cut the bill by roughly a fifth. Close the doors to rooms you are not using. Clean the filter each season — a clogged filter makes the fan work harder for less air. Run the quiet overnight mode in bedrooms; it caps the compressor and the noise at the same time.
The one structural decision that changes the bill for twenty years is sizing. An oversized unit costs more to buy and more every hour it runs. Check the size first, then quote the price. And if you are still heating with gas ducted in Victoria, the rebate for switching to reverse cycle is the biggest discount in the country right now.
FAQ
Running-cost questions, answered straight
How much does air conditioning cost to run per hour in Australia?
A modern 3.5 kW inverter split typically costs about 15–25 cents an hour once the room is at temperature, at 2026 electricity rates around 32 c/kWh. A large 7.1 kW living-area split runs roughly 35–50 cents an hour, and whole-home ducted about 70 cents to $1.10 depending on how many zones are open.
Is it expensive to run an air conditioner all day?
Less than most people guess. A correctly sized bedroom split running eight hours costs roughly $1.20–$2.00 a day. Inverters idle right down once the room holds temperature — the expensive first half hour is not what the whole day costs.
Is reverse cycle heating cheaper than gas in Australia?
For most homes now, yes. A modern reverse cycle unit delivers three to four units of heat per unit of electricity, which beats resistive electric heaters by two-thirds and undercuts most gas ducted systems at 2026 tariffs — which is exactly why Victoria pays households to switch off gas.
What temperature should I set my air conditioner to save money?
In summer, 24–25°C. Every degree colder adds roughly 5–10% to the running cost, so 21 instead of 24 can cost a quarter more for comfort you stop noticing in ten minutes. In winter, 18–20°C is the efficient band.
Does an oversized air conditioner cost more to run?
Usually, and it is less comfortable too. An oversized unit short-cycles: repeated hard starts, poor dehumidifying, clammy rooms. Correct sizing costs less upfront and per hour — check yours with our size calculator before believing any quote.
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