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What size ducted aircon
do you need?

Two taps: your home and your city. We give you the kW capacity, a zoning suggestion, and what ducted costs installed where you live.

Your home

Your city

Your ducted system

Answer both questions and your recommendation appears here instantly.

Transparent maths

How we calculate this

Sized by home, not guesswork

Whole-home capacity bands follow what Australian installers actually fit: 10–12kW for compact single-storey homes up to 16kW+ for large two-storey layouts.

Priced from your city's data

The cost range is your city's installed ducted range from our price database, single-storey homes sit toward the bottom, two-storey toward the top.

Zoning built in

Every recommendation assumes zoned design, day/night as the baseline, because an unzoned ducted system wastes capacity and running cost in every empty room.

A guide, not a site survey: ducted sizing is finalised with a heat-load calculation on site, which every quote through us includes before you commit to anything.

How ducted sizing works

Whole-home systems are sized on the conditioned floor area, storeys and zoning design, not just bedroom count. Two-storey homes push air further and lose more through the envelope, so they step up a band. When you sit between sizes, installers round up: a ducted unit that never works flat-out lasts longer and costs less to run.

Home	Typical size	Zoning
2–3 bed, single storey	10–12kW	Day / night zones
4 bed, single storey	12–16kW	Day / night zones
4 bed, two storey	14–18kW	Up / down + day / night
5+ bed / large open plan	16kW+	Individual room zoning

Ducted sizing questions

What size ducted aircon do I need?

As a working rule: 10–12kW covers a 2–3 bedroom single-storey home, 12–16kW a 4-bedroom single-storey, 14–18kW a 4-bedroom two-storey, and large or open-plan two-storey homes run 16kW and beyond. Ceiling height, insulation and glazing move the answer, which is why installers confirm sizing with a heat-load calculation on site.

How accurate is the cost estimate?

The range is your city's installed range from our price database, matched to your home size and storeys. Most standard installs land inside it; complex roof cavities, premium zoning and long duct runs move individual quotes. The exact number comes from quotes on your actual home, which is what the form below is for.

Does zoning change the size I need?

It changes what you pay to run more than what you install. Zoning lets a right-sized unit cool only occupied areas instead of the whole envelope, day/night zoning is the value sweet spot, and it's also why a well-zoned 14kW system often outperforms an unzoned 16kW one.

Get quotes for exactly this system

Your size recommendation is attached to the lead, installers quote the right capacity first time.

What size ducted aircon do you need?