What size air conditioner do I need — and what will it cost?
As a rough guide an air conditioner needs about 125–150 watts of capacity per square metre, so a typical lounge needs a 5–6 kW split system. Installed, a single split runs about $1,200–$4,800 depending on size, a multi-head system $4,200–$8,000, and ducted $10,000–$20,000. Use the calculator below to size your space, then get free quotes from local installers.
Floor area of the space. For ducted, use the whole-home floor area.
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.
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.