What Size Solar System Do I Need Calculator
Work out what size solar system you need before you shop. Answer a few questions about your bill and when you use power, and the calculator returns a recommended system size in watts (6,600W is a 6.6kW system), then prices it installed.
Your what size solar system do i need details
Your bill is the best guide to how much power you use.
If you use power at night, a larger system plus a battery captures more value.
Your estimate sits within the typical range.
Size your system to your usage, not just your roof. After rebates (STCs), a 6.6kW system is the most common Australian choice and usually pays for itself in a few years.
Where the money goes
Estimated breakdown for your configuration
💰 Ways to save
- Size to your actual bill, an oversized system that exports cheaply pays back more slowly.
- Federal STC rebates cut the upfront cost significantly, built into most quoted prices.
or from $34/week over 5 years , indicative finance
How we estimate this
Most Australian homes need a 6.6kW to 10kW solar system in 2026, costing roughly $4,000 to $15,000 installed after STC rebates, depending on size and components. Your power bill is the best guide to the right size.
Pricing reviewed: October 2026.
Doing more than just what size solar system do i need?
Build a combined estimate across every part of your project in one place.
Pricing reviewed October 2026. Indicative Australian costs, not a quote.
Understanding what size solar system do i needs in Australia
Most Australian homes need a 6.6kW to 10kW solar system in 2026, costing roughly $4,000 to $15,000 installed after STC rebates, depending on size and components. Your power bill is the best guide to the right size.
Size the system to your usage. If you are home during the day you use more solar directly; if you are out, a battery or larger system captures more value than exporting for a small feed-in tariff.
Frequently asked questions
What size solar system do I need?
Most Australian homes suit 6.6kW to 10kW, sized to your power bill and usage. A low bill may need 4.4kW; a high bill with evening usage may suit 10kW+ with a battery.
How much does a solar system cost in Australia?
Roughly $4,000 to $15,000 installed after STC rebates in 2026, depending on size and components. A 6.6kW system is the most common choice.
Are you a solar / trades business?
Everyone on this page is working out what what size solar system do i need costs because they are ready to hire. Put your business right beneath the calculator, in your state, so you are who they find. From $50/mo.