Roofing Calculator
Estimate roof squares, shingle bundles, underlayment, ridge caps, and material cost.
Roof Details
Common roofs
Ready to calculate
Enter roof dimensions or choose a preset.
Last updated June 9, 2026 by our expert review team
Roofing Takeoff Roadmap
| Step | Calculator uses | Verify before ordering |
|---|---|---|
| Footprint | length x width | Measure roof planes when the shape is cut up |
| Pitch factor | surface area multiplier | Use the actual pitch for each plane |
| Waste | cuts and layout allowance | Increase for hips, valleys, dormers, and short courses |
| Accessories | underlayment and caps | Starter, drip edge, flashing, vents, and fasteners |
Expert Contributors
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 June 2026
How we verify our calculatorsRoofing Material Takeoff Guide
A whole-roof order starts with footprint, converts to sloped roof area, then adds waste and accessory quantities.
Use this for planning. A roofer or supplier should confirm valleys, dormers, vents, flashing, and product-specific accessories.
Pro Tips
Use roof surface area, not house floor area. Pitch can add a lot of roof area over the same footprint.
A simple gable roof often starts around 10% waste. Hip roofs and cut-up roof planes need more room for angled cuts.
Bundles are shown only for asphalt shingles. Metal, tile, and slate orders need panel, tile, or slate-specific layouts from the supplier.
Use the shingle calculator when bundle count, warranty tier, and shingle weight are the main question.
Use the rafter calculator for framing length and board takeoffs before roofing starts.
How the Calculator Works
The calculator treats the roof as a simplified footprint with one pitch. For cut-up roofs, measure each roof plane and use this as a first-pass order check.
Roof area
length x width x pitch factor
Order squares
roof area x (1 + waste) / 100
Bundles
squares x bundles per square
Quick Reference
- 1 roofing square
- 100 sq ft
- Standard shingles
- about 3 bundles/square
- Underlayment roll
- default 400 sq ft
- Ridge cap bundle
- default 25 ft
- Default gable waste
- 10%
Cost per Square by Material
Material ranges are planning placeholders. Local supplier quotes, tear-off, steep access, decking repairs, and labor can dominate the final job price.
Roof Replacement Cost
Replacement quotes usually include more than shingles. Tear-off, disposal, deck repairs, ice barrier, flashing, ridge ventilation, steep access, and labor can move the price more than the material choice alone.
Material order
squares, bundles, caps
What this calculator estimates first.
Replacement labor
tear-off and install
Usually priced by square and roof complexity.
Job extras
decking, flashing, vents
Often added after inspection or quote walk-through.
Real-World Roofing Examples
Small ranch
40 x 25 ft, 4/12 gable, 10% waste
11.6 squares, 35 bundles
Straight gable roof with architectural shingles.
Two-story colonial
45 x 40 ft, 6/12 gable, 10% waste
22.1 squares, 67 bundles
More footprint and pitch, but still a simple shape.
Hip roof home
50 x 30 ft, 5/12 hip, 15% waste
18.7 squares, 57 bundles
Extra cuts at hips make the waste allowance matter.
Steep cabin
32 x 25 ft, 12/12 gable, 10% waste
12.4 squares, metal layout
Metal, tile, and slate need product-specific layouts.
Roofing Calculator FAQ
What is a roofing square?
One roofing square is 100 square feet of roof surface. Roofers use squares because shingles and many roofing materials are ordered that way.
Is this different from the Shingle Calculator?
Yes. Roofing is the whole-roof takeoff for area, squares, underlayment, caps, and cost. Shingle focuses on bundle ordering details.
Why does pitch change the area?
A sloped roof has more surface area than its flat footprint. The pitch factor converts footprint into roof surface.
How much waste should I add?
Use about 10% for a simple gable, 15% or more for hip roofs and cut-up roofs, and verify with the installer.
Should I replace the roof or overlay new shingles?
A tear-off costs more up front but lets the roofer inspect decking, flashing, and underlayment. Overlays may be restricted by code, warranty terms, roof condition, or the number of existing layers.
Why do metal and tile show no bundles?
Bundles are an asphalt-shingle packaging unit. Metal panels, tile, and slate need a product-specific layout.
Does this include flashing and vents?
No. The calculator estimates major quantities. Flashing, vents, drip edge, tear-off, and repairs need a job-specific list.
Roofing Takeoff Mistakes
Using floor area as roof area
A roof footprint still needs the pitch factor. Steeper roofs can add a lot of surface area.
Forgetting hip and valley cuts
Complex roof shapes need more waste than a straight gable.
Counting shingles but not accessories
Underlayment, starter, ridge or hip caps, vents, flashing, and fasteners all belong in the order plan.
Treating the supplier quote as optional
Product exposure, bundle coverage, and accessory packaging vary by manufacturer.
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.