Roofing Shingle Material Calculator

Calculate the number of shingle squares, bundles, nails, and ridge cap bundles needed for your roofing project based on roof dimensions and pitch.

Roof Length (ft)

Roof Width / Rafter Run (ft) (horizontal distance from eave to ridge)

Roof Pitch (rise per 12 in run, e.g. 6 for 6:12)

Number of Roof Sides / Planes

Waste Factor (%)

Ridge Length (ft) (total length of all ridges and hips)

1. Slope Factor
Slope Factor = √(pitch² + 12²) / 12
Converts horizontal (plan) area to actual sloped surface area.

2. Gross Roof Area
Area = Length × (Width × Slope Factor) × Number of Sides

3. Adjusted Area
Adjusted Area = Gross Area × (1 + Waste% / 100)

4. Squares
Squares = Adjusted Area / 100 (1 square = 100 sq ft)

5. Bundles
Bundles = ⌈Squares × 3⌉ (standard 3-tab: 3 bundles/square)

6. Nails
Nails = ⌈Squares × 320⌉ (4 nails × ~80 shingles/square)
Nail Boxes = ⌈Nails / 300⌉ (~300 nails per 1-lb box of 1¾" roofing nails)

7. Ridge Cap Bundles
Ridge Bundles = ⌈Ridge Length / 35⌉ (1 bundle covers ~35 linear ft)

8. Underlayment
Rolls = ⌈Squares / 4⌉ (1 roll of 15-lb felt covers ~400 sq ft)

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