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Shingle calculator

Shingles sell in squares (100 sq ft) and bundles (often 3 bundles per square for common asphalt). Pitch turns a flat footprint into more surface. Waste covers starter, ridge, hips, and cuts. Pair this with roof pitch if you still need the slope factor. This page will not walk your ridge or price tear-off.

sq ft
sq ft
Optional — skips pitch factor when set
in
in
12%
0510152025

+12% so you don't come up short

ORDER ESTIMATESHINGLES
Squares to order15.0
Bundles46
Roof surface1341.64 sq ft
Pitch factor1.118
Waste12%
How it calculates
surface = footprint × √(1+(rise÷run)²) or entered surface; squares = surface × (1 + 12%) ÷ 100; bundles = ceil(squares × bundles/sq).

Estimate only — not a contractor bid. Confirm bag yields and local codes before you pour or order.

When to use

Re-roof materials list; comparing 3-tab vs architectural bundle counts; adding waste before a color lot disappears.

When not to

Metal panel roofs — different coverage. Steep roofs you cannot safely measure — hire the measure. Insurance claim sketches as legal documents — adjuster rules apply.

Assumptions

1 square = 100 sq ft. Default 3 bundles / square (editable — architectural packs differ). Pitch factor from rise/run or manual surface entry. Waste default 10–15%.

Worked examples

Example 1

1,200 sq ft footprint, 6/12 factor ≈ 1.118, waste 12%
→ surface ≈ 1,342 → with waste ≈ 1,503 → 15.0 squares → 45 bundles at 3/sq

Ridge cap is often extra linear feet — check the bundle type.

Example 2

known 20 squares surface, waste 10%, 4 bundles/square specialty
→ 22 squares → 88 bundles

How it calculates

Convert footprint to surface with pitch, add waste, divide into squares and bundles.

  1. Enter footprint area (or known surface area).
  2. Set rise/run for the pitch factor, or skip if surface is already known.
  3. Set bundles per square and waste; read squares and bundles.
surface area = footprint × pitch_factor (or entered surface area)
squares = surface × (1 + waste%) ÷ 100
bundles = ceil(squares × bundles_per_square)

Common traps

  1. Bundles per square is not always three — read the wrapper.
  2. Footprint ≠ surface without pitch factor.
  3. Valleys and dormers eat more than a flat rectangle waste %.
  4. Starter and hip/ridge may be different SKUs.

Next tool

Pitch / slope factor → roof pitch calculator.

Asphalt driveway (different asphalt) → asphalt calculator.

FAQ

Often three for common asphalt; confirm on the package.

Related

Estimate only — not a contractor bid or engineered takeoff. Confirm bag yields and local codes before you pour or order.