How many bundles of shingles per square?

Standard 3-tab and most architectural shingles require 3 bundles per roofing square (100 sq ft). Some premium heavyweight shingles may require 4 bundles per square — check the coverage listed on the bundle wrapper. Always add 10-15% to your total for waste from ridge caps, hip cuts, and valley cuts.

How do I calculate roof area for shingles?

Measure your house footprint area (length times width) and multiply by the roof slope factor. For a 4/12 pitch, multiply by 1.054. For a 6/12 pitch, multiply by 1.118. For an 8/12 pitch, multiply by 1.202. For hip roofs, add an additional 10% for the extra waste generated by angled hip cuts.

How long do architectural shingles last?

Quality architectural shingles carry 30-year limited warranties and typically last 25 to 30 years in most US climates with proper installation and adequate attic ventilation. Premium lines from GAF, CertainTeed, and Owens Corning offer 50-year or lifetime warranties, though actual lifespan depends heavily on climate, ventilation, and UV exposure.

What is the difference between 3-tab and architectural shingles?

3-tab shingles have a flat, uniform appearance and cost less ($25-35 per bundle) but offer only 60-80 mph wind resistance and 20-25 year warranties. Architectural (dimensional) shingles have a layered, textured look that mimics wood shakes, offer 110-130 mph wind ratings, and carry 30-50 year warranties. Most new construction and reroofing projects now use architectural shingles.

How much does a new shingle roof cost?

For a typical 1,500 to 2,000 sq ft roof, materials alone (shingles, underlayment, drip edge, nails, ridge cap) cost $2,000 to $4,000. Professional installation adds $3,000 to $7,000 depending on roof complexity and region. Total installed cost typically ranges from $5,000 to $12,000 for architectural shingles.

Do I need to remove old shingles before reroofing?

Most codes allow up to two layers of asphalt shingles. However, tearing off the old layer is recommended because it allows inspection of the sheathing for rot, ensures proper underlayment installation, and reduces the dead load on the roof structure. Many roofing warranties require a tear-off for full coverage.

Shingle Calculator

Shingle calculator: How many bundles do I need? Free estimator for standard shingles — converts square metres to bundles.

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Enter Your Measurements

How to Use This Calculator

1Calculate total roof area including all slopes.
2Enter in square feet.
3Click Calculate — result shows bundles (3 bundles = 1 square = 100 sq ft).

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About This Material

Asphalt shingles are the most popular residential roofing material in North America, covering over 75% of all homes. They come in two main styles: 3-tab shingles (flat, uniform appearance, 20-25 year warranty, lower cost) and architectural/dimensional shingles (layered, textured appearance, 30-50 year warranty, more wind resistant). Shingles are sold in bundles, with 3 bundles covering 1 roofing square (100 sq ft). Architectural shingles cost $30 to $50 per bundle, while premium designer shingles run $50 to $100 per bundle. Popular brands include GAF Timberline, CertainTeed Landmark, and Owens Corning Duration. Shingle color affects attic temperature — lighter colors reflect more heat in southern climates. Wind ratings range from 60 mph for basic 3-tab to 130 mph for high-wind architectural shingles. Ridge cap shingles are sold separately (about 20 linear feet per bundle) and are needed for all ridge and hip lines.

Next Steps:

Roofing Underlayment Calculator →Drip Edge Calculator →

Installation Tips

•Start from the eave, working up to the ridge.
•Offset vertical joints by 6" minimum between courses.
•Use 4 nails per shingle in standard conditions, 6 in high-wind areas.
•Install ridge cap shingles separately (sold in separate bundles).

Common Mistakes to Avoid

Not adding waste — always order extra for ridge cap, hips, and valleys.
Under-nailing in high-wind zones.
Not using ice and water shield in the first 2 feet from eave in cold climates.

Shingle Calculator

How to Use This Calculator

About This Material

Installation Tips

Common Mistakes to Avoid

Frequently Asked Questions

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