Roof Shingles Calculator
(e.g., 33.3 for 3-tab, 32.3 for architectural)
(Typically 10-15% for cuts, errors, complex roofs)
Understanding Your Roof Shingles Needs
Estimating the correct number of shingles for your roof is crucial for any roofing project. Ordering too few can cause delays, while ordering too many leads to unnecessary waste and cost. Our Roof Shingles Calculator helps you get a precise estimate, ensuring you have enough materials without overspending.
How to Use the Calculator
- Total Roof Surface Area (sq ft): This is the total area of your roof's surface. For a simple gable roof, you might measure the length of one side and the slant height from the eave to the ridge, then multiply by two. For more complex roofs, you'll need to measure each plane individually and sum their areas. If you have blueprints, the total roof area might be listed.
- Shingle Coverage per Bundle (sq ft): Shingles are typically sold in bundles, and each bundle covers a specific square footage. This value can vary based on the type of shingle. For common 3-tab asphalt shingles, a bundle often covers around 33.3 square feet. Architectural or laminate shingles might cover slightly less, around 32.3 square feet per bundle. Always check the manufacturer's specifications for the exact coverage of your chosen shingles.
- Waste Factor (%): It's almost impossible to install a roof without some material waste due to cuts, trimming around vents or chimneys, and potential errors. A waste factor accounts for this. For simple gable roofs, 10% is often sufficient. For more complex roofs with multiple valleys, hips, or dormers, a waste factor of 15% or even 20% might be more appropriate.
What is a "Square" of Shingles?
In roofing, a "square" is a unit of area equal to 100 square feet. Shingles are often quoted or sold in terms of how many bundles make up a square. For example, if a bundle covers 33.3 sq ft, then 3 bundles would cover approximately 100 sq ft (1 square).
Factors Affecting Shingle Quantity
- Roof Complexity: Roofs with many angles, valleys, hips, dormers, or skylights will naturally require more cuts and thus a higher waste factor.
- Shingle Type: Different types of shingles (3-tab, architectural, designer, wood, metal) have varying dimensions and coverage rates per bundle.
- Installer Experience: An experienced roofer might generate less waste than a novice, though a waste factor is always recommended.
- Roof Pitch: While our calculator uses total surface area, a very steep roof can sometimes be more challenging to work on, potentially leading to slightly more waste.
Example Calculation:
Let's say you have a roof with a total surface area of 1,800 sq ft. You're using 3-tab shingles that cover 33.3 sq ft per bundle, and you've estimated a 12% waste factor due to a few valleys.
- Area with Waste: 1,800 sq ft * (1 + 12/100) = 1,800 * 1.12 = 2,016 sq ft
- Bundles Needed: 2,016 sq ft / 33.3 sq ft/bundle = 60.54 bundles. Rounded up, you'd need 61 bundles.
- Squares Needed: 2,016 sq ft / 100 sq ft/square = 20.16 squares.
Using this calculator will help you plan your roofing project efficiently and accurately.