Free Tool

Solar System Size Calculator

Find out exactly how many solar panels your home needs and how much roof space they'll require.

How would you like to enter your usage?

Monthly Bill ($) Monthly kWh

Average Monthly Electric Bill

Average Monthly kWh Usage — check your electric bill

kWh

Your Region

Energy offset target

80%Smaller system

100%Recommended

110%Future-proof

Panel Wattage

Standard350W

High Efficiency400W

Premium440W

How this works: System size = (Annual kWh ÷ 365 ÷ Peak Sun Hours) ÷ inverter efficiency. Panel count = System watts ÷ panel wattage. Roof space based on ~18 sq ft per panel. Actual sizing may vary based on roof angle, shading, and specific equipment.

Get a professional site assessment to confirm the perfect system size for your home.

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