Roofing Shingle Calculator

Calculate shingles (squares and bundles) for a roof.

BUNDLES NEEDED
— bundles
shingle bundles

Usage Tip

Always add 10–15% for waste and ridge caps, and measure from the drip edge.

THE MATH
Squares = Area × pitch × (1 + waste) ÷ 100
Where: pitch factor 1.05–1.25  •  1 square = 100 sq ft
• 3 bundles per square
• Add 10–15% for waste and ridge caps
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The calculators and tools on Formula Factory are provided for general guidance and informational purposes only. Results are estimates based on standard formulas and the values you enter — they do not constitute professional engineering, electrical, or architectural advice. Always verify calculations with a qualified professional before making decisions for any safety-critical, code-compliance, or commercial application. Formula Factory makes no representations or warranties as to the accuracy or completeness of any result, and accepts no liability for errors, omissions, or any outcomes arising from reliance on this information.