Free Roofing Calculator - Calculate Materials & Costs
Calculate roofing squares and bundles needed, plus material costs and weights.
Formula & Methodology
Estimates the total surface area of a pitched roof and converts it into standard roofing squares (100 sq ft) and shingle bundles.
- Roof Area = Flat Area × Pitch Multiplier
- Squares = Roof Area / 100
Worked Example
Using the Roofing Calculator: apply the formula above to your input values. For instance, Roof Area = Flat Area × Pitch Multiplier, then Squares = Roof Area / 100. The tool performs each step instantly and shows the result.
Frequently Asked Questions
How much roofing material do I need?
It estimates roof area from your dimensions and pitch, then converts to squares (100 sq ft each) of shingles or panels.
What is a roofing square?
A square equals 100 square feet of roof area, the standard unit roofers use to quote and order materials.
How much extra should I order?
Add about 10-15% for waste, cuts, ridges and valleys, and more on complex or steep roofs.