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Wood Shingle Triple-Lap Exposure Calculator

Calculate wood shingle bundle quantity for a given weather exposure, scaled from standard bundle coverage.

Computed in your browser — nothing you enter is uploaded. Figures are presented for United States against IRC 2024, and every formula is cited under regulatory standards below.

Last verified 2026-08-26 · v1.0.0

Market
Imperial · sales tax

Shingle bundles needed

44 bundles

Check your inputs

Bundle coverage ratings vary by manufacturer, shingle length, and grade — verify the standard coverage and reference exposure against your specific product's bundle label before ordering.

Scaled coverage per bundle
25 ft²

With the figures above, the shingle bundles needed comes to 44. The method behind this is well established, though site conditions and material batches will move it somewhat. This is calculated for United States and cites IRC 2024. Building in another market? Change the selector above so the units and code reference follow.

Estimated cost — your price

This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.

Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — confirmed fixes become pinned regression tests.

[Schema Verified] Computed in alignment with American Concrete Institute (ACI 318-19) formulas and International Residential Code (IRC 2024) spatial boundaries.

Regulatory standards & verification citations

  • Wood shingles are laid in a triple-lap pattern; bundle coverage is rated at a standard exposure (commonly 5in for 16in shingles) and scales linearly with actual exposure ÷ standard exposure

Your workspace

Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.

Frequently asked questions

Why does bundle coverage scale with exposure?
A bundle contains a fixed quantity of shingles, so increasing the weather exposure (the visible portion of each shingle) covers more roof area per bundle, while a tighter exposure covers less — coverage scales linearly with actual exposure divided by the reference exposure the bundle rating was based on.
What is a triple-lap pattern?
Wood shingles are laid so that any point on the roof is covered by three overlapping layers of shingle, which is what allows the exposure (the exposed course height) to be less than the full shingle length while still shedding water reliably.
Should I buy extra bundles beyond this calculated number?
This calculator gives the base coverage estimate only — it doesn't add waste for cutting at hips, valleys, ridges, or rakes, so always add a cutting-waste allowance on top of this number per your job's roof complexity.