Free planning tool
Estimate your solar panel system size
Enter your typical electricity use and local sun conditions for a simple starting estimate. This is planning guidance—not an installation quote.
Assumes a 20% system-loss allowance for inverter, temperature, wiring, dust and other real-world factors. Local shading, roof orientation, tariffs and rules can materially change the final design.
How to use this estimate
Start with the total kilowatt-hours shown on your electricity bill—not the dollar amount. Peak sun hours are not the length of the day; they are the average daily sunlight equivalent for your location. If you are unsure, 4 to 5 peak sun hours is a reasonable exploratory starting range in many sunny regions.
What this calculator does not include
- Roof space, shading and structural constraints
- Battery capacity or outage coverage
- Local utility rules, export rates and incentives
- Final equipment selection and installer design