You'll need about
124
m² of covering (with 10% waste)
113
m² roof area
42
packs of covering
Turn your roof measurements into a priced estimate your customer can approve. Build a free estimate.
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How this is calculated
footprint (ft²) × pitch factor = actual roof area · roof area ÷ 100 = roofing squares · squares × 1.10 = squares to order (waste) · 3 bundles per square for standard shingles. The pitch factor accounts for the slope — a steeper roof has more surface area than its footprint.
This is a planning estimate — always confirm against your supplier and the specifics of the job before ordering.
Roofing calculator: FAQ
What is a roofing square?
A roofing square is 100 square feet of roof surface. Roofers and suppliers quote materials in squares, so a 2,000 sq ft roof is 20 squares.
How many bundles of shingles do I need?
Standard three-tab and architectural shingles come three bundles to the square (100 sq ft). So a 20-square roof needs about 60 bundles — plus roughly 10% extra for waste, ridge caps, and starter strips.
How does roof pitch change the amount?
The steeper the roof, the more surface area it has above the same footprint. A 6/12 pitch roof has about 12% more area than a flat footprint; a 12/12 has about 41% more. This calculator applies the pitch factor for you.
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