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Roofing Calculator

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Estimate roofing shingles bundles needed based on roof slope, area, and waste percentage.

Roofing Shingles Calculator | Bundles & Waste Estimate

Use this roofing shingles calculator to estimate how many bundles of shingles are required for full roof coverage. Once activated, you will be able to enter roof area, slope, and waste percentage to get a complete estimate.

Roofing Shingle Calculator

Units:
meters along the ridge
meters across the building
Degrees (e.g. 25–45° typical). Leave blank to ignore slope.
Commonly 10–15% extra for cuts, hips and valleys.
Metric: m² per bundle (typical 2.5–3 m²). Imperial: bundles per roofing square (~3).

Enter building size and slope to estimate roofing shingles.

This tool assumes a simple gable roof with two equal slopes. Complex roofs (hips, dormers, multiple sections) should be measured section by section or checked by a roofing professional.

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Shingle Coverage Basics

One bundle of asphalt shingles covers approximately:
3.0 to 3.5 m² depending on brand and style.

Roof area increases with slope:

  • Low slope (10–20°): +5% material
  • Mid slope (20–30°): +10%
  • Steep slope (30°+): +12–15%

Example

Roof area (flat): 100 m²
If slope is mid (25°): add 10%
100 × 1.10 = 110 m² adjusted area

If each bundle covers 3.3 m²:
110 ÷ 3.3 ≈ 33 bundles

Waste Percentage

Standard waste:

  • Straight layout: 8–10%
  • Valleys/edges: 12–15%
  • Complex roof geometry: 15–18%

When to Add Extra

  • Valleys and multiple pitch lines
  • Skylights and chimneys
  • Patterned shingles

Ventilation Note

Roof lifespan depends heavily on attic ventilation and underlayment integrity.

FAQs

How accurate is shingle estimation?
For standard roof shapes and slopes, estimates are typically reliable within ±10%.

Do different shingles vary in coverage?
Yes, always check manufacturer coverage per bundle.

What about hip and ridge caps?
These require additional bundles, typically listed separately on packaging.