The Roofing Calculator helps you calculate roofing squares needed based on roof size and pitch. Simply fill in the fields above and click Calculate to get an instant result.
This calculator is part of Calculate Wiki’s Construction Calculators collection.
What You’ll Need
- Building Length (ft)
- Building Width (ft)
- Roof Pitch
- Waste Allowance (%)
Formula Used
Roof area = Building Length × Width × Pitch Multiplier × (1 + Waste % ÷ 100)
Squares = Roof area ÷ 100
Example Calculation
Using example inputs — Building Length = 40 ft; Building Width = 25 ft; Roof Pitch = 6; Waste Allowance = 10 % — the Roofing Calculator returns:
| Value | Result |
|---|---|
| Building footprint | 1,000 sq ft |
| Pitch multiplier | 1.118 |
| Roof surface area | 1,230 sq ft |
| Squares needed | 12.3 |
12.3 roofing squares. Roof surface area: 1,230 sq ft (1 square = 100 sq ft).
Helpful Information
Results from the Roofing Calculator are estimates based on standard formulas used in the construction calculators field. For projects with significant cost, health, or safety implications, consider verifying results with a qualified professional.