Free Online Tool

Roofing Calculator — Estimate Materials Instantly

Get accurate roofing material estimates for shingles, metal roofing, and more. Used by contractors, homeowners, and DIY builders.

3
Roof Types
2
Material Types
10+
Pitch Options
100%
Free to Use

Enter Roof Details

Measurement System
Roof Type
Waste Percentage

Your Results

Ready to Calculate

Enter your roof dimensions and click Calculate to see material estimates.

Frequently Asked Questions

Measure the length and width of your house at the eaves (the outer edges). For pitched roofs, select your roof type and pitch. The calculator automatically adjusts for slope using proper pitch factor formulas.
A roofing square is a unit of measurement equal to 100 square feet. It is the standard way roofing materials are measured and sold. For asphalt shingles, 3 bundles typically cover 1 square.
Standard 3-tab asphalt shingles require 3 bundles per roofing square (100 sq ft). Architectural/laminated shingles may require 4 bundles per square. This calculator uses the standard 3-bundle-per-square rule.
Roof pitch is expressed as rise over run (e.g., 6/12 means the roof rises 6 inches for every 12 inches of horizontal run). The pitch factor is calculated using the formula: √((rise/run)² + 1), which determines the actual surface area of the sloped roof.
Standard waste allowance is 10% for most roofs. Simple gable roofs may only need 5%, while complex roofs with many valleys, hips, and penetrations may require 15% or more. This calculator lets you choose your waste percentage.
Yes! Select "Metal Roofing" as your material. The calculator uses standard 3ft × 8ft (24 sq ft) metal panel sizes to estimate the number of sheets needed. Enter your price per sheet for cost estimates.
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