How to Calculate Shingles Needed for Your Roof
Order the right number of bundles: avoid project delays from under-ordering and wasted money from over-ordering.
The Basic Formula
Bundles Needed = (Roof Area in Sq Ft / 100) x 3 x Waste Factor
Where: 100 sq ft = 1 square, 3 bundles = 1 square, waste factor = 1.10 to 1.15
Determine Your Roof Area
If you already know your roof area in square feet, skip to Step 2. Otherwise, use our Roof Area Calculator, follow the manual roof area calculation guide, or multiply your footprint by the pitch multiplier.
Convert to Roofing Squares
Divide your total roof area by 100 to get the number of roofing squares.
Example: 1,800 sq ft / 100 = 18 squares
Calculate Field Shingle Bundles
Most asphalt shingles (both 3-tab and architectural) are packaged so that 3 bundles cover 1 square (100 sq ft). Some heavy designer shingles require 4 or 5 bundles per square -- check the specific product packaging.
Example: 18 squares x 3 bundles/square = 54 bundles
Add Waste Factor
Waste comes from cuts at valleys, hips, rakes, and around penetrations.
| Roof Complexity | Waste % | Description |
|---|---|---|
| Simple gable | 10% | Two slopes, no valleys, few penetrations |
| Moderate (hip or cross-gable) | 12-15% | Hip ridges, one or two valleys, some dormers |
| Complex | 15-20% | Multiple valleys, dormers, turrets, skylights |
Example: 54 bundles x 1.12 (moderate waste) = 60.5, round up to 61 bundles
Calculate Starter Strip Shingles
Starter strips run along the eaves and rakes under the first course. Measure the total linear feet of all eaves and rakes.
Example: 200 LF of eaves and rakes / 105 LF per bundle = 1.9, round up to 2 bundles
Calculate Hip and Ridge Cap Shingles
Ridge and hip caps cover the peak and hip lines. Measure the total linear feet of all ridges and hips.
Example: 75 LF of ridge and hips / 25 LF per bundle = 3 bundles
Complete Example
Scenario: 1,800 sq ft hip roof with one valley
Skip the Math
Enter your roof dimensions and get field shingles, starters, ridge caps, underlayment, nails, and more calculated instantly.
Shingle Bundle Estimator
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Bundles needed