Roofing
Shingle Calculator
Your measurements : area, area per package. Your estimate : packages to buy, area to purchase, extra area for waste.
How the calculation works
Shingle Calculator
round up(Area × (1 + Waste allowance / 100) ÷ Area per package)Before you order
- A simple roof with one uniform pitch is assumed. Length and width are horizontal plan dimensions; overhang is horizontal on every side. Valleys, hips, dormers and overlaps need separate allowances.
- Planning estimate only. This is not a structural design, a safety approval or a local code check.
Worked example
- Area
- 20 m²
- Area per package
- 3.1 m²
- Waste allowance
- 10 %
Packages to buy 8
Area to purchase 24.8 m²