Roofing Calculator
Calculate how many shingle bundles, underlayment rolls, nails, drip edge, and ridge cap you need for any gable, hip, or multi-section roof. Adjustable pitch from flat to 12/12. Free, no sign-up required.
Multiplies footprint area to get actual roof surface.
Bundle count per roofing square (100 sqft).
Typical: $30-50 architectural, $25-35 3-tab, $55-80 designer.
Typical: $75-110 per 10-square synthetic roll.
🏠 Total Shingle Bundles
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bundles
Roof Area
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Squares
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Underlayment
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Ridge Cap
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Nails (lb)
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Drip Edge (ft)
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Starter Strip (ft)
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📊 Project Breakdown
| Component | Value |
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Ridge cap length includes both ridge and hip lines for hip roofs. Pitch multiplier is industry-standard (RSMeans 2026).
💡 What this means
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🛒 Get roofing materials for your project
🛒 See shingles & roofing supplies on Amazon →📝 How to use this roofing calculator
- Choose your roof type — rectangle/gable for simple homes, hip for hip roofs (more complex, more ridge), gable-only for triangular roofs, or multi-section for L-shaped or T-shaped homes.
- Select measurement units — feet & inches for US projects, meters for metric.
- Enter building dimensions — footprint length × width (rectangle/gable/hip) or building length, width, ridge length, and overhang (gable only / hip). For multi-section, enter each section's dimensions.
- Pick the roof pitch — standard 6/12 for most homes. Steeper pitches need more material because the roof surface is larger than the footprint below.
- Set shingle type and waste factor — architectural is most common (3 bundles/square). 10% waste is typical for hip roofs; 5% for simple gable.
- Set your local prices — cost per bundle and per underlayment roll.
- Click Calculate — see total shingle bundles, squares, underlayment rolls, ridge cap, nails, drip edge, starter strip, and total project cost.
📌 5 tips for buying roofing materials
- ✓ Buy all shingles from the same lot number. Even the same color and brand can have slight batch variation that shows up as visible stripes on a finished roof. Get all the bundles you need at once, mix bundles from different pallets as you go, and keep receipts in case you need to return unopened bundles.
- ✓ Calculate pitch from inside the attic, not from the ground. The on-the-roof measurement can be off by 1-2 inches of rise per foot, and that compounds across the whole roof. Use a 2-foot level and a tape measure: 12 inches of level + the rise over that 12 inches = pitch. A roof that looks "about 6/12" from the ground is often 7/12 or 8/12 in reality.
- ✓ Add 10% waste for hip roofs, 15% for complex cut-ups. Valleys, hips, dormers, and chimneys eat material. A simple gable with no valleys is closer to 5% waste. Hip roofs typically run 10-12% waste even for experienced roofers. Cut-up roofs with multiple dormers and valleys can hit 15% or more.
- ✓ Don't skip the underlayment or ice & water shield. Synthetic underlayment is the 2026 standard for most residential applications ($75-110 per 10-square roll). In snow-belt areas (IBC climate zones 5+), code requires ice & water shield at least 24 inches inside the interior wall line of the eave — that's typically 2 rolls of ice & water plus 1-2 rolls of synthetic for the rest of the field.
- ✓ Schedule delivery for 1-2 days before installation. Shingles are heavy (60-80 lb per bundle), and storing them on-site for weeks is a hassle. Most suppliers and home improvement stores deliver direct to the roof with a boom truck for a small fee, saving hours of carrying bundles up ladders.
Disclaimer: This calculator provides estimates for educational purposes only. Actual roofing needs may vary based on roof complexity, valley and hip counts, local code requirements (ice & water shield, fire-rated underlayments, high-wind nailing patterns), waste from cuts, and shingle exposure choice (5-5/8 inch for standard architectural, 4-inch for 3-tab). Always buy 10-15% extra for breakages, and consult local building codes for required underlayment type and fastening patterns. This tool is not a substitute for professional contractor advice or a written estimate from a licensed roofer.
Related Tools
Roofing projects usually touch more than just shingles. These calculators cover the rest of the home improvement workflow — from measuring roof area to estimating materials and project costs.
- Area Calculator — compute the square footage of any roof footprint, wall, or building before estimating roofing needs.
- Square Footage Calculator — measure total building footprint, roof, and living area for any home improvement estimate.
- Paint Calculator — estimate gallons of paint and primer for your home's exterior after a new roof goes on.
- Concrete Calculator — estimate cubic yards for the foundation, footings, or post-holes that the roof sits on.
- Drywall Calculator — estimate drywall sheets, mud, tape, and screws for interior projects inside the same home.
- Tile Calculator — figure out how many boxes of tile, thinset, and grout for bathrooms and kitchens in the same home.
- Roof Replacement Cost Calculator — estimate the full cost of a new roof including labor, materials, and tear-off of the old roof.
- Home Renovation Cost Calculator — plan a full home renovation budget across all trades, from roof to drywall to flooring.
- Insulation Calculator — determine the right R-value and amount of insulation for the attic or roof deck before closing up the ceiling.
- Home Maintenance Cost Calculator — budget the full annual cost of owning and maintaining a home, including roof repairs.
- Home Equity Calculator — see how a new roof (one of the highest-ROI projects) affects your home's value.