Calculate total roof surface area for gable, hip, shed, and flat roofs with adjustable pitch. Get accurate square footage and roofing squares instantly.
4
Roof Types
10+
Pitch Options
2
Systems
100%
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Enter Roof Dimensions
Roof Area Results
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Enter your building dimensions and roof type to calculate surface area.
Total Roof Area
0 sq ft
Roofing Squares
0 squares
Pitch Factor
0
Overhang Area
0 sq ft
Calculation Summary
Roof TypeGable
Building Size0 × 0
Roof Pitch6/12
Pitch Factor1.118
Total Area0 sq ft
Frequently Asked Questions
To calculate roof area, multiply the building footprint (length x width) by a pitch factor that accounts for the roof slope. For example, a 6/12 pitch has a factor of 1.118. Multiply the footprint by the factor to get the total roof surface area. Our calculator does this automatically.
A roofing square is a unit of measure equal to 100 square feet of roof surface. Roofing materials are typically quoted in squares. To convert square footage to squares, divide the total roof area by 100. Most residential roofs range from 15 to 40 squares.
A gable roof has two sloping sides that meet at a ridge, forming a triangle at each end. A hip roof has four sloping sides, with all sides meeting at the ridge. Hip roofs have slightly more surface area than gable roofs for the same building footprint and pitch.
Steeper roof pitches increase the total surface area because the roof surface is longer. The pitch factor accounts for this: a 4/12 pitch has a factor of 1.054, while a 12/12 pitch has a factor of 1.414. A steeper pitch means more roofing materials needed.
Standard roof overhangs range from 6 to 24 inches (0.5 to 2 feet). A 12-inch overhang is common for most homes. Our calculator includes overhang in the total building dimensions, so be sure to include it when measuring for the most accurate results.