What size air conditioner do I need — and what will it cost to install?
Aircon installation costs in Australia range from about $1,200 for a small split system to $4,800 for a large one, $4,200–$8,000 for a multi-head system, or $10,000–$20,000 for ducted. As a rough guide you need about 125–150 watts of cooling per square metre, so a typical lounge wants a 5–6 kW split. Use the calculator below to size your space and price the install — or if your existing unit has died, see the typical repair costs further down — then get free quotes from local installers.
Floor area of the space. For ducted, use the whole-home floor area.
Air conditioning repair costs (Australia)
| Repair / service | Typical cost | Notes |
|---|---|---|
| Service call / diagnosis | $100 – $200 | Many repairers put this toward the repair if you go ahead |
| Full service & clean | $100 – $320 | Coil and filter clean, drain flush, pressure and electrical checks |
| Capacitor, sensor or control board (PCB) | $150 – $500 | The common “won't turn on” and “keeps tripping” faults |
| Refrigerant leak — find, fix & regas | $400 – $1,200 | By law the leak must be repaired before the gas is recharged |
| Typical split-system repair | $200 – $700 | Depends on the fault and parts availability |
| Typical ducted-system repair | $500 – $1,500 | Zone motors, ductwork and controls add complexity |
Indicative ranges, October 2026. Repairs are quoted after diagnosis and vary with brand, parts availability and access — if a repair quote approaches half the cost of a new unit on an ageing system, ask for a replacement quote too.
Common questions
What size air conditioner do I need for a room?+
A common rule of thumb is about 125–150 watts of cooling capacity per square metre, so a 20 m² bedroom needs roughly a 2.5–3.5 kW unit and a 35 m² open living area around 5–6 kW. Sunny, west-facing or poorly-insulated rooms, and high ceilings, need more — an installer will confirm the exact size.
How much does it cost to install a split system?+
Supplied and installed, a single wall-mounted split system runs roughly $1,200–$2,500 for a small 2.5–3.5 kW unit and $2,500–$4,800 for a larger 7–9 kW one. A back-to-back install on an existing circuit is cheapest; long pipe runs or new wiring add cost.
Split system vs ducted — what's the cost difference?+
A single split cools one room for $1,200–$4,800 installed. To cool a whole home you'd use multiple splits (a multi-head system is about $4,200–$8,000) or ducted reverse cycle, which is typically $10,000–$20,000+ depending on the home's size and number of zones.
How much do air conditioning repairs cost?+
A service call with diagnosis typically runs $100–$200. Common electrical faults — a failed capacitor, sensor or control board — cost about $150–$500 to fix. A typical split-system repair lands between $200 and $700, while ducted-system repairs run $500–$1,500 because of zone motors, ductwork and controls. Repairs are quoted after diagnosis.
Can I just get my air conditioner regassed?+
No — refrigerant doesn't get used up, so low gas always means a leak. Under Australia's refrigerant handling rules, a licensed (ARCtick) technician must find and repair the leak before recharging the system. Leak detection, repair and regas typically costs $400–$1,200 depending on where the leak is.
Should I repair or replace my air conditioner?+
A common rule of thumb: if the unit is 10+ years old and the repair quote is more than about half the cost of a new installed unit (a small split system runs $1,200–$2,500 installed), replacement is usually the better money — newer units are also significantly more efficient to run. For a newer unit under warranty, repair first.
Do I need an electrician to install air conditioning?+
Air conditioner installation is done by a licensed refrigeration/air-conditioning technician, and any new or upgraded electrical circuit must be done by a licensed electrician. Many install businesses cover both. Always use licensed trades — it's required for warranty and safety.