Roof shingle calculator
Estimate shingle bundles from your roof area, waste allowance and bundles per square, plus starter and ridge cap bundles from eave, rake, ridge and hip lengths.
Roof and plan areas up to 1,000,000 m² (about 10.76 million ft²), waste from 0 to 50%, 1 to 10 bundles per square, edge lengths from 0 to 10 km and coverage per starter or cap bundle up to 1,000 m, up to 1 billion bundles. Pitch from 0 to 48 per 12, 0 to 75 degrees or 0 to 400%. Calculated on your device; download a JSON report and a results CSV. This calculator uses the measurement fields only. Results update as you type. Up to 1,000,000 characters.
Your result
How to use Roof shingle calculator
- Enter the sloped roof area, or the plan area with the pitch.
- Set the waste allowance and the bundles per square printed on the shingle wrapper.
- Enter eave, rake, ridge and hip lengths with the starter and cap coverage per bundle.
- Review squares and bundles, then download the JSON report or the CSV.
Useful next steps
Squares and bundles
A square is 100 ft² of roof. Three bundles per square is most common for three-tab and many laminated shingles, and heavier shingles need four or five (Fine Homebuilding, Mike Guertin, How to Estimate Materials for Roofing Projects, checked 16 October 2026). The calculator adds your waste allowance, converts to squares and rounds bundles up: 2,100 ft² plus 10% is 23.1 squares, or 70 bundles at three per square.
Starter and ridge cap
Starter runs along the eaves, and along the rakes only when your shingle maker calls for it. Hip and ridge cap is taken from the ridge and hip lengths; the same article puts a typical cap bundle at about 35 linear feet. Enter the coverage printed on your wrappers, because both vary by product.
Plan area and pitch
If you only know the footprint, choose plan area and pitch. The sloped area is the plan area × √(1 + (rise ÷ run)²) (OpenStax Precalculus 2e, 5.4, checked 16 October 2026), which assumes every plane has the same pitch. Use the roof area calculator for mixed pitches.
What is not included
Valley extras, underlayment, drip edge, flashing and nails are separate items. The tool does not check minimum slopes, wind ratings or local roofing rules. A square is 100 ft² (Wikipedia, Square (unit), checked 16 October 2026); conversions use NIST SP 811.