Roofing Calculator

Inputs

Results update as you type.

Building
ft
ft
in
Roof
%
Roof section30 ftrise 8 ft12 inPitch 26.6° · length 40 ftmyconstructioncalculator.com
Diagram updates as you type.

Results

Check the working before you order.

Roof area incl. wastage
1,652.9ft²
Roofing squares (100 ft²)16.53 sq
Shingle bundles (3 per square)50 bundles
Rafter length (gable, eave to ridge)17.89 ft
Roof angle26.6 °
Price This optional: add your own prices

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Working
  1. Plan incl. overhang = (40.00 + 2 × 1.00) × (30.00 + 2 × 1.00) = 42.00 × 32.00 = 1,344.0 ft²
  2. Pitch factor = √(1 + pitch²) = √(1 + 0.5000²) = 1.1180
  3. Roof area = 1,344.0 × 1.1180 = 1,502.6 ft²; + 10% = 1,652.9 ft²
  4. Squares = 1,653 ft² ÷ 100 = 16.53

Results are estimates for planning and material ordering only. They are not a substitute for structural design or approval by a qualified engineer. Read the full disclaimer.

Roofing Calculator byMy Construction Calculator: free construction calculators with the working shown.