Roof Shingle Calculator
Roof Parameters
Calculation Results
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How to Calculate Shingles for a Roof
- Roof area = length × width of the footprint (including overhangs) × the pitch factor √(1 + (rise ÷ run)²).
- Squares = roof area ÷ 100 (one square covers 100 sq ft of roof).
- Bundles = squares × 3 for 3-tab and architectural shingles (each bundle covers about 33 sq ft), or × 4 for premium and luxury shingles.
- Waste: 10% for gable and flat roofs, 15% for hip and mansard roofs (more cuts).
- Ridge & hip cap, starter and drip edge: ridge cap = ridge length + 10% (on hip roofs, ridge plus the four hips); starter strip and drip edge = perimeter + 10%.
For metal, tile or slate, use the roofing calculator, which orders those by the square.
Shingle Calculator Examples
Example 1: Gable roof, architectural shingles
40 × 30 ft, 6:12
- Roof area: 1,341.64 sq ft = 13.4 squares
- Bundles: 41 before waste, 45 with 10% waste
- Ridge cap: 44 ft · Starter strip and drip edge: 154 ft each · Underlayment: 4 rolls
- Nails: about 3,840-4,720 (260-320 per square ordered, including waste)
Example 2: Hip roof, 3-tab shingles
40 × 30 ft, 8:12
- Roof area: 1,442.22 sq ft = 14.4 squares
- Bundles: 44 before waste, 50 with 15% waste
- Ridge & hip cap: 115 ft · Starter strip and drip edge: 154 ft each · Underlayment: 4 rolls
- Nails: about 4,310-5,310 (per square ordered, including waste)
Example 3: Large hip roof, architectural shingles
50 × 40 ft, 35°
- Roof area: 2,441.55 sq ft = 24.4 squares
- Bundles: 74 before waste, 85 with 15% waste (premium shingles at 4 per square: 98 / 113)
- Ridge & hip cap: 150 ft · Starter strip and drip edge: 198 ft each · Underlayment: 7 rolls
- Nails: about 7,300-8,980 (per square ordered, including waste)
Example 4: Metric measurements
12 × 9 m, 30°, gable, 3-tab
- Roof area: 1,342.34 sq ft (124.7 m²) = 13.4 squares
- Bundles: 41 before waste, 45 with 10% waste
- Ridge cap: 44 ft · Starter strip and drip edge: 152 ft each · Underlayment: 4 rolls
- Nails: about 3,840-4,730 (per square ordered, including waste)
Shingle Costs and Materials Checklist
| Shingle | Installed per square (100 sq ft) | Bundle price |
|---|---|---|
| 3-tab asphalt | $300-$500 | $27-$45 |
| Architectural | $400-$600 | $33-$85 |
Labor is about $2-$3 per sq ft ($200-$300 per square). Example 1 (13.4 squares) costs about $5,400-$8,000 installed with architectural shingles, before tear-off.
Source: HomeGuide, "Roofing Shingles Cost", updated November 2025.
- Shingles: squares × 3 bundles (4 for some premium and luxury lines; check the wrapper).
- Starter strip along the eaves and rakes, and hip & ridge cap shingles by the linear foot.
- Underlayment: #15 felt covers about 400 sq ft per roll, #30 felt about 200, synthetic about 1,000.
- Ice and water shield where code requires it, and drip edge around the perimeter.
- Nails: about 260-320 per square ordered, including waste (4 per shingle; 6 in high-wind zones).