Roof Shingle Calculator — Individual Shingle Count
Enter your roof area, shingle dimensions, weather exposure and a waste allowance to find the exact number of individual shingles and bundles to buy.
sq ft
in
in
in
%
Individual shingles including waste allowance
- 1
Coverage per shingle
(36 × 5.5) ÷ 144 = 1.375Width × exposure (inches) ÷ 144 converts sq in to sq ft of covered area per shingle. - 2
Gross area with waste
1,200 × (1 + 10%) = 1,320 - 3
Shingles needed
⌈1,320 ÷ 1.375⌉ = 960
How does this calculator work?
Divide your total roof area by the coverage each shingle provides (width × exposure ÷ 144 sq ft), add a waste allowance (typically 10%), and round up. Divide that count by the shingles per bundle (often 26–33) to find bundles to purchase.
Formula
How this is calculated
Each shingle covers only the portion of its face that is left exposed to the weather — the "exposure." The rest is hidden under the row above. Coverage per shingle in square feet is (width × exposure) / 144 (dividing by 144 converts square inches to square feet). Dividing the total roof area by this figure gives the minimum shingle count; adding the waste allowance (typically 10%) accounts for cuts at rakes, ridges and valleys, and for breakage.
Bundles are estimated from the same coverage figure: a standard bundle covers 33.3 sq ft (one-third of a roofing square). If you know your exact shingles-per-bundle from the packaging, you can back-calculate more precisely. This calculator uses the standard three-bundles-per-square (33.3 sq ft per bundle) assumption and rounds up.
Note that roof area here should be the actual sloped surface area, not the flat footprint. If you have only the footprint dimensions and pitch, use the Roofing Shingles & Squares Calculator first to convert footprint to sloped area, then use that result here. Waste percentages depend on roof complexity — simple gables typically need 10%, while roofs with many hips, dormers or skylights can need 15–20%.
Frequently asked questions
Exposure is the part of each shingle row left uncovered (visible). A 3-tab shingle 12 in tall is typically installed at 5–5.5 in exposure, so about half the shingle is hidden under the course above. More exposure means fewer shingles per area but less protection; manufacturer specs define the recommended range.
It varies by product. Most standard 3-tab shingles pack about 26 shingles per bundle (three bundles cover a 100 sq ft square). Thicker architectural shingles have more per bundle at a lower coverage rate. Always check your specific product packaging.
Ridge and hip caps are usually sold as separate cap shingles or cut from regular shingles. A 10% waste factor covers most of the extra; add another 5–10% if your roof has many ridges, hips or complex valleys.
Also known as
TG we-Calculate Editorial Team. (2026). Roof Shingle Calculator — Individual Shingle Count [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/roof-shingle-calculator
TG we-Calculate Editorial Team. "Roof Shingle Calculator — Individual Shingle Count." TG we-Calculate. 2026. https://we-calculate.com/calculator/roof-shingle-calculator.
TG we-Calculate Editorial Team, "Roof Shingle Calculator — Individual Shingle Count," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/roof-shingle-calculator
@misc{wecalculate_roof_shingle_calculator, title = {Roof Shingle Calculator — Individual Shingle Count}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/roof-shingle-calculator}}, year = {2026}, note = {TG we-Calculate} }
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