Roof Area Calculator

Calculate total roof area and usable area for solar panels based on roof dimensions and pitch. Estimates how many solar panels your roof can accommodate.

Roof Length (ft)

Roof Width (ft)

Roof Pitch

Obstructions (sq ft)

Gross Roof Area

1265 sq ft

Usable Solar Area

911 sq ft

Max Solar Panels

52 panels

Gross area = 40×30 × 1.054 (pitch factor) = 1265 sq ft. Usable area accounts for setbacks, obstructions, and shading (×0.75 factor). Each 400W panel needs ~17.5 sq ft.

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