Roof Space Calculator
Calculate how much roof area you need for solar panels and the maximum number of panels that fit your roof.
Results
Visualization
How It Works
Not all roof space is usable for solar panels. Building codes require setbacks from edges (typically 3 feet), and obstructions like vents, chimneys, and skylights reduce available area. A good rule of thumb is 85% of measured roof area is usable. Each standard residential panel is approximately 17.5 square feet (3.25 x 5.4 feet).