Shingle Calculator
The material take-off by shingle TYPE — field bundles, ridge cap, starter, and nails, with the ladder-load truth about what a bundle weighs.
Shingle Calculator
Results recalculate instantly on every keystroke. Nothing you type is transmitted.
What this result does not account for
- Asphalt shingles only — metal, tile and shake are different trades.
- Assumes 3-tab exposure for the shingle-per-square figure.
- No tear-off tonnage or dump-fee model.
In short: A 20-square roof at 15% waste: 23 squares — 69 bundles of 3-tab or standard architectural at 3 per square, 92 if you step to a designer line at 4. Ridge cap 60 lf → 2 bundles, starter 120 lf → 2 more, 7,360 nails at four per shingle. Cost: $2,530.00 at $110 a square.
Formula
squares = ⌈squares × (1 + waste%)⌉
field bundles = squares × bundles per square (3 or 4)
ridge = ⌈lf ÷ 35⌉; starter = ⌈lf ÷ 105⌉ — separate orders
nails = squares × ~80 shingles × 4 (or 6)
[('3 / square', '3-tab and standard architectural'), ('35 lf', 'ridge cap per bundle — never in the field count'), ('80 lb', 'the ladder-carry ceiling on any bundle'), ('320 / 480', 'nails per square, standard / high-wind')]
Worked Example
- Take pitch-adjusted squares from the Roofing page.
- Add waste: 10% simple, 15% with valleys, 20% complex.
- Multiply by bundles per square — 3, or 4 for designer.
- Order ridge at 35 lf per bundle, starter at 105.
- Nail 4 per shingle; 6 in high-wind zones.
20 squares at 15% waste → 23 squares → 69 field bundles (3-tab or arch), 92 designer; ridge 2 + starter 2 bundles; 7,360 nails; $2,530.00 at $110/square.
Strengths & Limits Of This Model
Where this engine is strong
- Type switcher with the honest 3-vs-4-5 bundle law
- Ridge and starter NEVER smuggled into field bundles
- Nail count from the exposure, not a guess
Where it stops
- Asphalt family only
- No valley/hip metal take-off
Practical Use Cases
Re-roofs
Bundle order from a known square count.
Type swaps
3-tab vs architectural vs designer.
Trim take-offs
Ridge and starter, separately.
High-wind zones
The 6-nail nail count.
Delivery checks
Bundle counts against the drop.
Methodology & Editorial Standards
Field bundles = ceil(squares × (1 + waste%)) × bundles-per-square, with the 3-or-4-or-5 switch as a free-entry term (3-5 enforced). Ridge and starter compute at the sourced 35 and 105 lf per bundle and print as separate orders. Nails assume ~80 shingles per square (5-in 3-tab exposure) at the 4-or-6 nail law. Cost = squares × free-entry price per square. Nonpositive squares and waste past 30% refused.
Computation runs in IEEE-754 double precision at full internal precision; rounding to two decimal places occurs strictly at the display layer, so no cumulative drift enters the result. All monetary outputs use accounting presentation — grouped thousands, two decimals, negatives in parentheses — so figures can be transcribed directly into a model or working paper. Division-by-zero and out-of-domain inputs return an em-dash rather than a misleading number.
This engine was reconciled against an independent reference implementation and hand-verified for the worked example above before release. Our full five-stage review process is published on the About Us page.
Disclaimer. This calculator is provided for informational and modelling purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Verify all figures with a qualified professional before acting on them.
Shingle Calculator — 9 Expert FAQs
9 analyst-written answers to the questions practitioners actually ask — optimised for voice and answer-engine retrieval.
How many bundles of shingles are in a square?
Three — for 3-tab AND standard architectural, each bundle covering 33.3 ft². Heavier designer lines run 4-5 bundles per square; the label on the bundle is the law.
Do ridge cap shingles count in the bundle total?
No — ridge and starter order separately. Plan about 35 linear feet of ridge per cap bundle and about 105 feet of eave per starter bundle.
How many nails per square of shingles?
About 320: roughly 80 three-tab shingles to the square at 5-in exposure, four nails each. High-wind zones drive six nails per shingle — about 480 per square.
How much waste should I add?
10% on a simple gable, 15% once valleys or hips enter, 20% on cut-up roofs. Architectural shingles cannot be bent back like 3-tab over hips — cuts cost real material.
Why are bundles capped at 80 pounds?
A roofer carries one up a ladder, all day. That human limit — not coverage — is why designer shingles need more bundles to cover the same square.
How much does a square of shingles cost?
3-tab ships in the $90-120 per square band, architectural above it — bundles run $25-45 and $35-70 respectively. This page prices YOUR quote per square.
What goes under the shingles?
Felt or synthetic underlayment, ice-and-water shield at eaves and valleys — that layer belongs to the Roofing page’s take-off. This page starts where the deck is dressed and the shingles begin.
How many shingles come in a bundle?
About 26-27 three-tab shingles — 80 to the square across three bundles. Architectural bundles hold fewer, heavier laminates, which is why the square, not the shingle, is the counting unit.
Shingle page or Roofing page?
The Roofing page turns footprint and pitch into squares, bundles and felt — the roof. This page starts from those squares and details the MATERIAL: type, trim, nails. They share the 3-bundles-per-square law.