Bundles Needed
45
Squares
14.76
Total Cost
$1,800
Common pitches: 4:12 (moderate), 6:12 (standard), 8:12 (steep)
Typical: 10% for simple roofs, 15-20% for complex shapes
Inputs
Result
Area = 40 × 30 × √(1 + 0.25) = 1,200 × 1.118 = 1,341.6 sq ft. Squares = 13.42 × 1.1 waste = 14.76. Bundles = ⌈14.76 × 3⌉ = 45. Cost = 45 × $40 = $1,800.
Inputs
Result
Area = 24 × 20 × √(1 + 0.111) = 480 × 1.054 = 505.9 sq ft. Squares = 5.06 × 1.1 = 5.57. Bundles = ⌈5.57 × 3⌉ = 17. Cost = 17 × $30 = $510.
Divide your roof area by 100 to get squares, then multiply by 3 bundles per square (for standard shingles). A 2,000 sq ft roof needs 20 squares × 3 = 60 bundles. Add 10-15% waste for cuts and starter strips.
| Roof Area | Squares | Bundles (3-Tab) | Bundles + 10% Waste |
|---|---|---|---|
| 1,000 sq ft | 10 | 30 | 33 |
| 1,500 sq ft | 15 | 45 | 50 |
| 2,000 sq ft | 20 | 60 | 66 |
| 2,500 sq ft | 25 | 75 | 83 |
| 3,000 sq ft | 30 | 90 | 99 |
One bundle of standard 3-tab or architectural shingles covers about 33.3 sq ft (3 bundles per 100 sq ft square). Premium/designer shingles may require 4 bundles per square, covering only 25 sq ft per bundle.
Shingle costs per square (100 sq ft): 3-Tab: $90-120, Architectural: $100-150, Premium/Designer: $200-400. Material only — installation adds $150-300 per square for labor.
| Shingle Type | Material/Square | Installed/Square | Warranty |
|---|---|---|---|
| 3-Tab | $90–$120 | $350–$450 | 20–25 years |
| Architectural | $100–$150 | $400–$550 | 30–50 years |
| Premium/Designer | $200–$400 | $550–$800 | 50+ years |
| Impact-resistant | $150–$250 | $450–$650 | 30–50 years |
A roofing square equals 100 square feet of roof area. It is the standard unit for ordering roofing materials. For example, a 2,000 sq ft roof is 20 squares. Always account for roof pitch — steeper roofs have more actual area.
| Roof Pitch | Multiplier | 1,200 sq ft Footprint | Extra Area |
|---|---|---|---|
| 4:12 (low) | 1.054 | 1,265 sq ft | +5.4% |
| 6:12 (standard) | 1.118 | 1,342 sq ft | +11.8% |
| 8:12 (steep) | 1.202 | 1,443 sq ft | +20.2% |
| 10:12 (very steep) | 1.302 | 1,563 sq ft | +30.2% |
| 12:12 (45°) | 1.414 | 1,697 sq ft | +41.4% |
Read our guide
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Last Updated: Mar 9, 2026
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