How Many Roof Shingles Do You Need?

Roofing materials are sold by the bundle and quoted by the square (100 sq ft). Most bundles of architectural shingles cover 33.3 sq ft — three bundles per square. To estimate your requirement, divide the total roof area by bundle coverage, round up to whole bundles, and add a waste allowance for valleys, hips, cutoffs, and mistakes.

Choosing a Waste Factor

Simple gable roofs: add 10%. Complex roofs with hips, valleys, and dormers: add 15–20%. Steep pitches increase cutting waste and may warrant a higher factor. Buying a few extra bundles is inexpensive insurance — a mid-job shortage means a second delivery, possible color-mismatch risk, and delayed progress.

Beyond the Shingles

Your material estimate should also include underlayment, drip edge, flashing, ridge caps, and nails. Labor typically represents 40–60% of total roofing cost. Use this calculator to establish the shingle budget, then add roughly $3.50–$5.50 per square foot for a fully installed asphalt shingle roof.