Roof Shingle Calculator (Squares & Bundles)
Roofing squares, shingle bundles, felt and nails from the house footprint and pitch.
A 6/12 pitch silently adds 12% area; a 12/12 adds 41% — never order off the floor plan alone. Add a bundle of matching shingles for ridge caps unless you buy dedicated ridge stock.
Formula
Roof Shingle Calculator (Squares & Bundles) is a free roof shingle calculator for civil engineers, contractors and quantity surveyors — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Roof Shingle Calculator (Squares & Bundles)
Roofing squares, shingle bundles, felt and nails from the house footprint and pitch. The calculation implements true area = footprint × √(1 + (pitch/12)²) × (1+waste); 1 square = 100 ft² = 3 bundles (ARMA Residential Asphalt Roofing Manual). A 6/12 pitch silently adds 12% area; a 12/12 adds 41% — never order off the floor plan alone. Add a bundle of matching shingles for ridge caps unless you buy dedicated ridge stock.
How to use Roof Shingle Calculator (Squares & Bundles)
- 1Enter Roof footprint (plan area) in m².
- 2Enter Pitch (rise per 12 run) (6 = a 6/12 roof).
- 3Enter Waste (hips, valleys, starters) in % (10% gable · 15%+ hips/valleys).
- 4Read Shingle bundles (3/square), Roofing squares, True roof area instantly — no submit button needed.
- 5Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Roof Shingle Calculator (Squares & Bundles)?
- ✓Implements the standard formula — true area = footprint × √(1 + (pitch/12)²) × (1+waste); 1 square = 100 ft² = 3 bundles
- ✓Reference cited on-page: ARMA Residential Asphalt Roofing Manual
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Roof Shingle Calculator (Squares & Bundles) use?+
It computes true area = footprint × √(1 + (pitch/12)²) × (1+waste); 1 square = 100 ft² = 3 bundles, per ARMA Residential Asphalt Roofing Manual. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
A 6/12 pitch silently adds 12% area; a 12/12 adds 41% — never order off the floor plan alone. Add a bundle of matching shingles for ridge caps unless you buy dedicated ridge stock.
Does it include wastage?+
Yes — standard wastage/bulking factors are built in and stated in the formula line, so the quantity is an orderable number, not a bare geometric volume.
Is the Roof Shingle Calculator (Squares & Bundles) free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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