Shingle Calculator
Enter your roof area to get bundles, nails, and underlayment rolls. Adjust shingle type and waste factor to match your project.
Inputs
How the estimates are calculated
Bundles
Bundles = ⌈ (Area ÷ 100) × bundles_per_sq × waste_factor ⌉ 3 bundles per square for standard 3-tab and architectural asphalt shingles. Source: IKO Industries, verified June 2026.
Nails
Nails = Bundles × shingles_per_bundle × nails_per_shingle Standard architectural bundle ≈ 21 shingles. Nail count rounds up to nearest 5-lb box (approx. 1,000–1,200 nails per 5-lb box for 1¼″ roofing nails).
Underlayment
Rolls = ⌈ Area_with_waste ÷ 400 ⌉ Standard felt underlayment (#15 or #30) covers approximately 400 sq ft per roll with standard 2″ side laps.
Related Tools
- Roofing Calculator — calculate from footprint dimensions and pitch
- Roofing Squares Calculator
- Roof Area Calculator
Frequently Asked Questions
Standard architectural asphalt shingles use 4 nails per shingle for low-pitch roofs and 6 nails for steep pitches or high-wind zones. A bundle of standard architectural shingles contains roughly 20–22 shingles, so plan for 80–132 nails per bundle. This calculator uses 4 nails per shingle as the default.
Standard #15 or #30 felt underlayment rolls cover approximately 400 sq ft (one square = 100 sq ft per layer). Synthetic underlayment typically covers 1,000–10,000 sq ft per roll depending on the product. This calculator uses 400 sq ft per roll as the default (felt).
3-tab shingles are flat, single-layer shingles with three cutouts along the bottom edge. Architectural (dimensional) shingles are multi-layer, thicker, and more durable with a roughly 30-year warranty. Both types use 3 bundles per roofing square for standard products.
Starter strip runs along all eaves (bottom edges) of the roof. Measure your total eave length — for a simple gable roof that is 2 × the ridge length. Starter strip bundles typically cover 100–105 linear feet per bundle.