Roofing Calculator
Estimate roof surface area, roofing squares, shingle bundles, and material cost from your building's footprint and roof pitch.
Building footprint
Materials & cost
Standard 3-tab / architectural shingles: 3 bundles = 1 square (100 sq ft).
Flat footprint area: sq ft
Roof surface area: sq ft
Roofing squares (with waste):
Bundles needed:
Estimated material cost:
Pitch multiplier: ×
How this works
Roof surface area = footprint area × pitch multiplier (accounts for slope). One roofing square = 100 sq ft. A waste factor covers cuts, overlaps, and hips/valleys — 10–15% is typical for simple gable roofs, more for complex roof lines.