Pick your input mode − enter roof area directly if you have it, or enter footprint and pitch to calculate it. Choose shingle type and waste factor, then hit Calculate shingles for squares, bundles, underlayment, ridge cap, starter strip, drip edge, and fasteners. Optional ridge, eave, and rake lengths produce a full takeoff.
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How this calculator works
Shingles are sold in bundles, and bundles are grouped into squares. One roofing square is 100 square feet of finished roof surface, and a standard 3-tab or architectural shingle uses 3 bundles per square. The calculator converts your area (or footprint × pitch) into squares, applies your waste factor, multiplies by bundles per square for your shingle type, and adds the material lines that a squares-only calculation misses: underlayment, ridge cap, starter strip, drip edge, and fasteners.
Squares = (Roof area × (1 + Waste%)) ÷ 100 Bundles = Squares × Bundles per square (rounded up) True area from footprint = Footprint area × Pitch multiplier
The pitch multiplier is why you should never order based on footprint alone. At 6/12 the multiplier is 1.118 − a 12% shortfall on a footprint-based order. At 10/12 it is 1.302 − a 30% shortfall. The calculator handles the conversion automatically when you use footprint mode.
The complete shingle takeoff runs from area to squares to bundles to the full material list. The calculator handles all four stages.
Bundles per square by shingle type
Bundle coverage varies by shingle type and manufacturer. These are the industry-standard defaults the calculator uses. Always confirm on the bundle label before ordering — some premium or heavy-weight products vary.
Shingle type
Bundles per square
Coverage per bundle
Typical lifespan
Notes
3-tab asphalt
3
33.3 sq ft
20–25 years
Lightest, most economical
Architectural / dimensional
3
33.3 sq ft
30–50 years
Thicker profile, more common today
Designer
4–5
20–25 sq ft
30–50 years
Heavier, some brands vary — check label
Impact-resistant (Class 4)
3
33.3 sq ft
30–50 years
Hail-rated, may qualify for insurance discounts
Waste factor − why 10% is not enough on every roof
Waste covers offcuts, ridge and hip cuts, damaged shingles, and starter course overlaps. The right percentage depends on how many planes, valleys, and penetrations your roof has.
Roof complexity
Waste factor
What it covers
Simple gable roof, one ridge, no valleys
10%
End cuts, starter course, minor damage
Gable with dormers, or any roof with valleys
15%
Valley cuts, dormer cuts, waste at penetrations
Hip roof, multifaceted, or many penetrations
20%
Hip cuts, multiple plane intersections, higher offcut rate
Never round down. If the calculator says 22.3 squares, order 23. A single missed square costs a trip to the store and possibly a color-batch mismatch if the second order comes from a different production lot.
The full takeoff includes materials beyond shingles. The calculator outputs these based on your area and (for ridge/starter/drip edge) your optional linear-foot inputs.
Material
Coverage / unit
How it's calculated
Underlayment (synthetic)
400 sq ft/roll (varies 400–1,000)
Roof area ÷ 400, rounded up
Ridge cap
25 linear ft/bundle (standard)
Ridge length ÷ 25, rounded up
Starter strip
100 linear ft/bundle
Eave length ÷ 100, rounded up
Drip edge
10 linear ft/piece
(Eave length + Rake length) ÷ 10, rounded up
Roofing nails
~320 per square (3-tab), ~480 (architectural)
About 1 lb per 100 nails
Field note from the estimating desk: the most common shingle-order mistake is ordering by footprint instead of true roof area. On a 6/12 roof that under-orders by 12%, which on a 20-square job is nearly a full square of bundles — roughly $100–$200 in wasted trips and possible lot mismatch. Always use the pitch multiplier. The second mistake is using a 10% waste factor on a hip roof: hip cuts produce far more offcut than gable cuts, and 20% is standard for a reason. If your roof has more than two valleys, use 20% and thank yourself later.
Frequently asked questions
How many bundles of shingles do I need?
Divide your roof area (plus waste) by 100 to get squares, then multiply by bundles per square. Standard 3-tab and architectural shingles use 3 bundles per square. A 1,500 sq ft roof with 10% waste is 16.5 squares, so 51 bundles. Designer shingles use 4–5 bundles per square.
How many bundles are in a square of shingles?
3 bundles per square for 3-tab and architectural shingles. A square is 100 sq ft, so each bundle covers about 33.3 sq ft. Designer shingles may use 4–5 bundles per square, so check the bundle label. A typical pallet holds 30–40 bundles.
How many shingles are in a bundle?
For 3-tab shingles: about 26–29 shingles per bundle. Architectural shingles: about 21–24 per bundle. The difference is because architectural shingles are thicker and cover the same 33.3 sq ft with fewer pieces. Designer shingles vary by brand.
How many shingles do I need per square foot?
One square covers 100 sq ft. For 3-tab, that is 3 bundles covering 100 sq ft, or roughly 80–87 individual shingles. The shingle-count calculation is less reliable than the bundle-count because shingle sizes vary — work in bundles, not individual pieces.
How much extra shingles should I buy for waste?
10% for a simple gable roof. 15% if there are dormers or any valleys. 20% for hip roofs, complex multi-plane roofs, or anything with many penetrations. Never round down — order the next full square.
How many squares is a 1,500 sq ft roof?
15 squares (1,500 ÷ 100). With 10% waste, order 16.5 squares — so 17 squares, which is 51 bundles of 3-bundle shingles. This assumes the 1,500 sq ft is the true sloped roof area, not the footprint.
How do I calculate roof area from my footprint?
Multiply footprint area by the pitch multiplier. At 6/12 the multiplier is 1.118; at 8/12 it is 1.202; at 12/12 it is 1.414. A 1,200 sq ft footprint with a 6/12 roof has about 1,342 sq ft of true roof area. Use the footprint mode in the calculator above to do this automatically.
How many rolls of underlayment do I need?
Synthetic underlayment typically covers 400 sq ft per roll. Divide your roof area (with waste) by 400 and round up. A 1,500 sq ft roof with 10% waste needs 1,650 ÷ 400 = 4.125, so 5 rolls. #15 felt covers about 400 sq ft per roll; #30 felt covers about 200 sq ft.
How much does a bundle of shingles cost?
As of 2026 US averages: 3-tab $25–$40 per bundle; architectural $30–$55 per bundle; designer $50–$100 per bundle; impact-resistant $40–$70 per bundle. Prices vary by region and brand. Enter your price per bundle in the calculator for a project-specific total.
How many nails do I need per shingle?
4 nails per 3-tab shingle, or 6 nails for architectural shingles in high-wind zones. Nails must be long enough to penetrate the deck by 3/4 inch − typically 1–1/4 inch for new roofs and 1–3/4 inch for re-roofing over existing shingles.
Standards and sources
Bundle coverage, waste factors, and accessory material yields are drawn from manufacturer technical data and roofing industry standards. Key references:
Asphalt Roofing Manufacturers Association (ARMA) installation guidance − 3 bundles per square for standard shingles.
IRC R905 minimum pitch and installation requirements for asphalt shingles.
Synthetic underlayment coverage ranges from manufacturer data sheets (typically 400–1,000 sq ft per roll).
Nail pattern and penetration requirements from IRC Table R905.2.5.1.
BM
Builders Measures estimating team
Reviewed against ARMA installation standards and standard roofing estimating formulas. Bundle coverage varies by manufacturer − always confirm on the product label before ordering. Last reviewed October 2026.