Free Roof Area Calculator
Calculate actual roof surface area from building footprint and roof pitch. Uses the pitch multiplier for accurate results.
feet
feet
inches
Roof Surface Area
1,677 sq ft
Footprint Area1,500 sq ft
Pitch Factor1.1180
Roofing Squares16.8
Roof Surface Area vs Building Length
How to Calculate Roof Area
Formula
Roof Area = Footprint Area × Pitch Factor
Pitch Factor = sqrt(1 + (Rise/12)²)
This method converts the horizontal footprint into the actual surface area by accounting for the roof slope.
Example Calculation
A building 50 ft by 30 ft with a 6/12 roof pitch.
- 01Footprint area = 50 × 30 = 1,500 sq ft
- 02Pitch factor = sqrt(1 + (6/12)²) = sqrt(1.25) = 1.1180
- 03Roof area = 1,500 × 1.1180 = 1,677 sq ft
- 04Roofing squares = 1,677 / 100 = 16.8 squares
Frequently Asked Questions
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