How many shingles do I need? Calculate roofing materials and costs by pitch, type, and material. Get squares, bundles, underlayment, and a price estimate.
Roof Details
10% typical for gable roofs
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Last updated March 2026 by our expert review team
Materials only. Installation labor adds $150 to $400 per square.
Ehsan Ghazanfari
Licensed Structural Engineer
FISE-certified structural engineer with 11+ years designing bridges, retaining walls, and foundations. MSc from Aalto University.
See full profileHawkin
Certified Cost & Estimating Professional
AACE-certified estimator working with 20+ insulation companies including the two largest franchises in America.
See full profileUpdated March 2026
How we verify our calculatorsAlways add 10 to 15% waste factor. Hip roofs need 15%+ because angle cuts at the hips generate more offcuts than a simple gable.
Buy all shingles from the same production lot. Different lots can have slight color variation that becomes obvious once installed across the roof.
Never install new shingles over two existing layers. Most codes allow one overlay maximum. Two layers add 500+ lbs per square to the structure.
Before ordering shingles, verify your roof framing is sound. Use our rafter calculator to size your roof framing before ordering shingles.
Schedule roofing for dry weather between 40 and 85 degrees F. Shingles won't seal properly below 40 degrees F. After the re-roof, use our insulation calculator to size attic insulation.
Use synthetic underlayment instead of felt paper. It costs 20% more but won't wrinkle, tear, or absorb moisture during install delays.
Starter strips along eaves and rakes prevent wind uplift on the first course. Skipping them is the #1 reason warranty claims get denied.
Enter your house footprint dimensions and select the roof pitch.
Choose roof type (gable, hip, flat) and material. Waste auto-adjusts.
Get squares, bundles, underlayment rolls, ridge caps, nails, and cost range.
Formulas
Roof Area = Footprint x Pitch Multiplier x (1 + Waste%)
Squares = Roof Area / 100
Bundles = Squares x 3
How many squares of shingles do I need?
Measure your roof footprint (length x width), multiply by the pitch factor, add waste, then divide by 100. A 1,000 sq ft footprint with a 4/12 pitch and 10% waste needs about 11.6 squares.
What is a roofing square?
One roofing square equals 100 square feet of roof area. It takes 3 bundles of standard shingles to cover 1 square.
How does roof pitch affect material quantity?
Steeper pitches mean more actual surface area over the same footprint. A 12/12 pitch adds 41.4% more area compared to a flat roof, requiring significantly more materials.
What is the difference between 3-tab and architectural shingles?
Architectural shingles are thicker, last 25 to 30 years vs 15 to 20 for 3-tab, and cost about $10 to $30 more per square. They also provide better wind resistance (up to 130 mph). Use our board foot calculator if you need to estimate lumber for decking repairs.
How much does a new roof cost?
Material costs range from $90 per square (3-tab) to $1,200 per square (slate). Labor adds $150 to $400 per square depending on pitch and complexity. A typical 20-square architectural roof costs $5,000 to $11,000 installed. For other home projects, check our deck calculator.
How many bundles of shingles do I need?
Multiply the number of squares by 3. For example, 15 squares requires 45 bundles. Each bundle weighs 60 to 80 lbs for architectural shingles.
Do I need underlayment under metal roofing?
Yes. Synthetic underlayment is required under metal roofing to prevent condensation damage. Use one roll per 400 sq ft of roof area.
What waste factor should I use for a hip roof?
Use at least 15% waste for hip roofs. The angled hip ridges require diagonal cuts on every shingle at the hip line, generating more unusable offcuts than a gable roof.
A straightforward gable roof with 10% waste. Budget $1,390 to $2,085 for materials.
The 6/12 pitch adds 11.8% more area than a flat roof. Budget $2,214 to $3,321 for materials.
Hip roofs need 15% waste due to angled cuts at every hip line. Budget $1,868 to $2,802 for materials.
A 12/12 pitch adds 41.4% more area. Metal panels cost more upfront but last 40 to 70 years. Budget $3,734 to $8,712.
Ignoring the pitch multiplier
A 12/12 pitch adds 41.4% more surface area than a flat roof. Using footprint area alone means you'll be short by dozens of bundles on a steep roof.
Forgetting waste for hip roofs
Hip roofs need at least 15% waste factor. Every hip line requires diagonal cuts, and those offcuts are too small to reuse.
Not ordering ridge caps separately
Ridge caps are sold in separate bundles (25 linear ft each). Standard shingle bundles don't include ridge pieces.
Using wrong nail length for overlays
Overlay (re-roof over existing shingles) requires 1.75-inch nails to penetrate both layers. Standard 1.25-inch nails won't reach the decking.
Skipping underlayment on low-slope roofs
Roofs below 4/12 pitch need ice-and-water shield membrane, not just standard underlayment. Water moves slowly on low slopes and can back up under shingles.
Important Disclaimer
These estimates are for planning purposes only. Actual costs vary by location, material availability, and project complexity. Always get at least 3 local quotes. This calculator does not replace professional advice.