Construction calculator
Roofing Calculator
Estimate roof surface area from building dimensions and pitch, then add waste and convert the result into roofing squares or full bundles.
Enter roof dimensions and calculate.
Roofing example
Example: 40 ft × 30 ft building, no overhang, 4:12 pitch and 10% waste.
Plan area = 40 × 30 = 1,200 ft²
Pitch factor = √(1 + (4 ÷ 12)²) = 1.054
Roof surface area = 1,264.91 ft²
With 10% waste = 1,391.40 ft² = 13.91 roofing squares
Pitch factor = √(1 + (4 ÷ 12)²) = 1.054
Roof surface area = 1,264.91 ft²
With 10% waste = 1,391.40 ft² = 13.91 roofing squares
What is a roofing square?
In North American roofing, one roofing square equals 100 square feet of roof surface. The calculator shows roofing squares automatically when imperial units are selected.
Bundle coverage
Bundle coverage varies by product. Enter the coverage printed for the roofing product you plan to use and MetricFigure will round up to a whole number of bundles.