Example calculation
SolarLab uses the current project values to show how the recommendation changes.
Interactive calculator
Roof solar panel calculator
Estimate panel fit on one rectangular roof plane using panel dimensions, orientation and perimeter setbacks.
No account Instant result PDF export
1Tell us what you knowUse the simple fields first.
2See the recommendationSolarLab explains what the number means.
3Refine or downloadContinue only when the result makes sense.
1
Inputs
Enter what you know
Start with the simple fields. Open Advanced only when you need more control.
Do not rely on one number alone
Check the result against actual equipment and site conditions.
Is this installation-ready?
No. It is a planning estimate that should be verified by qualified professionals.
How was this calculated?
Calculation method
Formula
The calculator uses the displayed inputs and standard planning relationships.
Important assumptions
Read the methodology → Verify the final design against actual equipment data sheets, site conditions, and applicable requirements.