Solar Basics
How Many Solar Panels Does a House Need?
By SaveBill Editorial Team. Last updated 2026-11-10.
The number of panels follows from your electricity use and the panel rating.
The method 1. Divide monthly units by 96 to get kW (standard assumptions). 2. Multiply kW by 1000 and divide by panel watts. 3. Round up.
Worked examples A house using 300 units needs about 3.1 kW, so about 6 panels of 550 W. A house using 500 units needs about 5.2 kW and about 10 panels.
Check the roof Allow roughly 10 m² per kW on flat roofs. If the roof is smaller, the system is limited by space. Use the rooftop area calculator.
Panel wattage matters Higher-wattage panels reduce the count but are larger. Compare efficiency and warranty, not only watts. See solar panels.
Quick tool Try the size calculator.
FAQ ### Do I need to cover 100% of my usage? No. Many people size for a share, limited by roof or budget. ### Does a cloudy region need more panels? Possibly. Real output varies by site.
Sources and further reading
Figures here are illustrative and use stated assumptions. Check official sources for policy details.