How many shingles you need
Roofers measure in squares, where one square covers 100 square feet, and most asphalt shingles come 3 bundles per square. So: squares = roof area ÷ 100 (plus waste), and bundles = squares × 3. A 2,000 sq ft roof with 10% waste is about 22 squares, or 66 bundles.
How to use this calculator
Enter your total roof area in square feet (the actual sloped area, not the building footprint) and a waste percentage. The result shows bundles and squares. A steeper, more complex roof has more area than the footprint — use the roof pitch calculator to account for slope. Start from the building footprint measured by the square footage calculator.
How much waste to add
Add about 10% for cuts, ridges, hips and valleys — more (up to 15%) on complex roofs with many angles. Buy ridge caps and starter strips separately, as they're not counted in field shingle bundles.
Measure ridges, hips and eaves in linear feet as well, because ridge caps, starter strip, drip edge and underlayment are all ordered by length rather than by the square. Valleys, dormers and skylights each add cuts, and that is exactly where the extra few percent on a complex roof disappears. For slope expressed as a percentage instead, use the elevation grade calculator.
Frequently asked questions
- How many bundles of shingles do I need?
- Divide roof area by 100 for squares, add waste, then multiply by 3 bundles per square. A 2,000 sq ft roof with 10% waste is about 66 bundles.
- What is a roofing square?
- A square is 100 square feet of roof area, the standard unit for estimating and pricing shingles.
- How many bundles are in a square?
- Most asphalt shingles come 3 bundles per square, though some heavier shingles use 4.
- How much waste should I add for shingles?
- About 10% for a simple roof, and up to 15% for complex roofs with many hips and valleys.
- How do I turn my building footprint into roof area?
- Multiply the flat footprint by the slope multiplier for your pitch. A 6:12 roof multiplies by 1.118, so a 2,000 sq ft footprint is about 2,236 sq ft of actual roof surface.