How many square feet is a square of shingles?

One square equals 100 square feet of roof coverage. Three bundles typically cover one square for standard laminated shingles.

How does roof pitch affect shingle quantity?

Steeper pitches increase actual roof area versus flat footprint. Multiply footprint by sqrt(1 + (pitch/12)²) or use a pitch factor table.

How much shingle waste should I add?

Add 10% for simple gable roofs and 12–15% for hips, valleys, dormers, and steep pitches.

How do I measure roof footprint?

Measure the horizontal length and width of the building at the eaves. For complex roofs, break into rectangles or use measured plan area.

Roof Shingle Calculator | Bundles, Squares & Roof Area

Q: How many bundles of shingles do I need?

Divide roof surface area (after pitch) by 100 to get squares, multiply by bundles per square (usually 3 for architectural shingles), and add 10–15% waste for cuts and hips.

Roof Shingle Examples

Tap to load into this shingle bundle calculator.

Ranch Home

30 ft × 40 ft · 6/12 gable · 10% waste.

Bundles: ~45

Two-Car Garage

24 ft × 24 ft · 4/12 pitch.

Bundles: ~20

Steep Gable

24 ft × 36 ft · 10/12 · 12% waste.

Bundles: ~38

Hip Roof House

28 ft × 44 ft · 6/12 hip · 12% waste.

Bundles: ~50

How to Calculate Roof Shingles

Bundles = (Footprint × Pitch Factor × (1 + Waste%)) ÷ 100 × Bundles/Sq Pitch factor = √(1 + (rise÷run)²) · 1 square = 100 sq ft roof

Measure footprint length and width at the eaves (horizontal plan).
Select roof pitch (e.g. 6/12) or enter custom rise and run.
Apply pitch factor to convert footprint to roof surface area.
Divide by 100 for squares; multiply by bundles per square (typically 3).
Add 10–15% waste for hips, valleys, and starter courses.

Use the roof pitch calculator or pitch of a roof calculator to verify rise, run, and angle before ordering.

Roof Shingle Calculator FAQ

How many bundles of shingles do I need?

Find roof surface square feet, divide by 100 for squares, multiply by bundles per square (usually 3), and round up after adding waste for cuts and hips.

What is a square of shingles?

A square covers 100 sq ft of roof area. Most laminated shingles ship as 3 bundles per square; check your product label.

How does pitch change shingle quantity?

Steeper roofs have more surface area than the flat footprint. A 6/12 pitch adds about 12% area versus a flat plan; 8/12 adds about 20%.

How much waste should I order?

Use 10% on simple gable roofs and 12–15% on hips, dormers, or when using multiple shingle colors.

Roof Shingle Calculator

Roof Footprint

Ranch Home

Two-Car Garage

Steep Gable

Hip Roof House

How to Calculate Roof Shingles

Roof Shingle Calculator FAQ

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