How Many Solar Panels Can You Fit on Your Roof?

The short answer: most modern panels are around 1.7 to 1.8 metres tall and 1.1 metres wide, which is roughly 2 square metres each. A 6.6kW system of about 15 panels needs around 30 square metres of clear roof. A 10kW system (about 23 panels) needs around 46 square metres.

The rough numbers

These are ballpark figures using 440W panels:

• 6.6kW: about 15 panels, roughly 30 square metres
• 10kW: about 23 panels, roughly 46 square metres
• 13kW: about 30 panels, roughly 60 square metres

Newer panels with higher wattage need fewer panels for the same kW, so always count both the kW and the panel count.

Your roof is not a blank canvas

Here is what eats into your usable space:

• Vents, skylights, flues and antennas that you can’t put a panel on top of.
• Hips, valleys and ridges. Installers leave gaps around edges and ridges for safety and access.
• Shade from trees, neighbours and that giant gum your landlord loved.
• Orientation. North-facing roof planes are the best performers in Australia, with east and west good, and south-facing planes usually the weakest.
• Roof type and condition. Tin, tile and Colorbond all work, but they’re mounted differently.

It is Tetris, but with a ladder and a sun path.

How to check before you ask for a quote

• Look at your roof on a satellite map and count the roof faces.
• Note which direction each one faces.
• Look for shade at 9am and 3pm.
• Ask your installer for a panel layout drawing, not just a kW number.

A good quote should show how many panels go where, so you can see if the maths adds up.

No roof big enough?

Fewer panels doesn’t mean a bad system. Higher wattage panels can squeeze more kW into less space, split systems can use both east and west faces, and a lot of regional properties have the luxury of a shed roof or a ground-mount array out in the paddock.

Does it change by state?

The panel sizes are the same everywhere. What changes is wind. Cyclone-rated mounting is part of the picture across northern Queensland and northern WA, and exposed sites in Tasmania and NSW need their own wind checks. Your installer should design to your local wind region.

Next step

If you are wondering how many panels you actually need rather than how many fit, check our guide on choosing the right system size. Or send over your address and we’ll check your roof as part of a free assessment.

General information only, current at November 2026. Prices, rebates and tariffs change, so check current terms before you buy.