Roofing Calculator
Enter the footprint of the roof (the house plus overhangs, measured flat from above) and the pitch. The calculator scales it up for the slope to get the true roof area, then counts squares and bundles.
A roofing square is 100 sq ft. Most architectural and 3-tab shingles come 3 bundles to a square. Add 10% waste for a simple gable roof and 15% for hips and valleys.
How it’s calculated
- Roof area = footprint × pitch multiplier. At 6/12 the multiplier is 1.118.
- Squares = roof area ÷ 100. Bundles = squares × (1 + waste %) × 3.
Shingles for common roof sizes
- 500 sq ft
- 600 sq ft
- 700 sq ft
- 800 sq ft
- 900 sq ft
- 1,000 sq ft
- 1,100 sq ft
- 1,200 sq ft
- 1,300 sq ft
- 1,400 sq ft
- 1,500 sq ft
- 1,600 sq ft
- 1,700 sq ft
- 1,800 sq ft
- 1,900 sq ft
- 2,000 sq ft
- 2,100 sq ft
- 2,200 sq ft
- 2,300 sq ft
- 2,400 sq ft
- 2,500 sq ft
- 2,600 sq ft
- 2,700 sq ft
- 2,800 sq ft
- 2,900 sq ft
- 3,000 sq ft
- 3,100 sq ft
- 3,200 sq ft
- 3,300 sq ft
- 3,400 sq ft
- 3,500 sq ft
- 3,600 sq ft
- 3,700 sq ft
- 3,800 sq ft
- 3,900 sq ft
- 4,000 sq ft
- 4,500 sq ft
- 5,000 sq ft
Questions
- How many bundles of shingles are in a square?
- Three for most asphalt shingles; some heavy designer shingles are four or five.
- How do I measure a roof without climbing on it?
- Measure the house’s outside length and width, add the overhangs, multiply, and apply the pitch multiplier.
- How much does a new roof cost?
- Asphalt shingle roofs typically cost $4 to $8 per sq ft installed, so $400 to $800 per square, depending on region and tear-off.