How Big is a Square of Shingles: Understanding Roofing Measurements

Last updated on April 18, 2024

In this article, you will gain precise knowledge about the dimensions of a square of shingles, a common unit used in roofing.

roofing shingles bundle

Key takeaways:

  • One roofing square is equivalent to 100 square feet.
  • Three bundles of shingles cover one roofing square.
  • Roofers and contractors use roofing squares to calculate materials.
  • Calculate squares by dividing total square footage by 100.
  • Consider waste factor and shingle type for accurate estimates.

What Is a Roofing Square?

what is a roofing square

A roofing square is a unit of measurement used in the roofing industry to simplify the communication of roof size and the amount of materials needed. Here’s what you need to know:

  • One roofing square is equivalent to 100 square feet of roof surface.
  • To cover one square, it typically takes three bundles of standard three-tab asphalt shingles.
  • This measurement standardizes estimates and costs across different types of roofing materials besides shingles, such as tiles or metal sheets.
  • Roofers and contractors use this term frequently to calculate the number of materials required for a roofing project, without referring to square feet.

Understanding this term is crucial when planning a roofing project or discussing options with a professional. It ensures accuracy in material estimates and helps homeowners understand the scope of their project.

The Standard Dimensions of a Roofing Square

A roofing square measures 100 square feet. To visualize this, picture an area 10 feet by 10 feet. This measurement is industry-standard, regardless of the shingle type or material.

When purchasing shingles, they’re often sold by the square, not by the individual shingle or by square feet, which helps in estimating the amount needed for a roofing project.

Generally, a bundle of shingles covers roughly one-third of a roofing square—though this can vary depending on shingle size and type. Therefore, it typically takes three bundles of shingles to cover one roofing square.

However, always check the coverage information provided by the manufacturer, as heavyweight or premium shingles can require more bundles per square.

Calculating the Number of Squares for a Roof

To determine the number of squares on a roof, follow these steps:

1. Measure the length and width of each roofing section in feet. For irregular areas, break them down into geometrical shapes and then measure.

2. Multiply the length by the width to calculate the area of each section. Add the areas together to get the total square footage of the roof.

3. Divide the total square footage by 100, as one square of shingles covers 100 square feet. The result gives you the number of squares needed.

4. Include a waste factor of about 10% to account for cutting and trimming, especially for roofs with a lot of hips, valleys, and dormers.

5. Round up any fractional square to ensure you have enough material, as shingles are sold by the square, not by individual sheets.

Remember, accurate measurements and considerations for waste will help ensure you purchase the correct amount of material for your roofing project.

Choosing the Right Shingle Type for Your Roof Square

Selecting the appropriate shingle type for your roofing square is crucial for longevity, aesthetics, and protection. Three-tab asphalt shingles are commonly chosen for their cost-effectiveness and ease of installation. Architectural shingles, on the other hand, offer a multi-dimensional appearance and enhanced durability, which may be more suitable for areas with variable weather conditions. Metal or tile shingles can provide even greater durability and distinctive styles, but typically come at a higher cost and may require specialized installation.

Additionally, consider the weight of the shingles, as heavier materials such as slate or clay tiles may require additional structural support. The color and reflective properties of shingles should also factor into your choice, with lighter shades often contributing to more efficient energy use by reflecting sunlight. Always check for compatibility with local building codes and climate-specific requirements to ensure your selection is both compliant and optimal for your region’s conditions.

Estimating Shingles Needed Based On Roof Size

To accurately estimate the number of shingles needed for a roofing project, you’ll first need to measure the total square footage of the roof area. This includes the main body of the roof as well as any extensions or dormers.

Once the total area in square feet is determined, the following steps will help you understand how to proceed:

  • 1. Divide the total square footage of the roof by 100 to find the number of roofing squares required. Roofing materials are sold per square, with one square covering 100 square feet.
  • 2. Factor in waste: Account for approximately 10-15% extra shingles to cover waste, trimming, and potential errors. For roofs with more complex features, such as multiple valleys or peaks, consider a higher waste allowance.
  • 3. Use the shingle packaging to guide you: Shingle bundles typically contain enough shingles to cover one-third of a roofing square, though this can vary depending on shingle size and type. Check the bundle quantity details before making a purchase.
  • 4. Consider the specific shingle exposure: Exposure refers to the portion of each shingle that is exposed to the weather. Some architectural shingles have different coverage specifications and may require more bundles per square.

By following these points, you’ll ensure that you purchase an adequate amount of shingles to complete your roofing job without a significant surplus. Remember that it’s beneficial to have a few spare shingles available for repairs or replacements down the line.


How many bundles of shingles are in a square?

Three bundles of shingles make up one roofing square.

How big of a roof is 20 squares?

A roof that is 20 squares is approximately 2,000 square feet in size.

What is the measurement of a square of shingles?

A square of shingles measures 10 x 10 feet, or 100 square feet.

What is 30 squares of shingles?

Thirty squares of shingles refer to a roof area of 3,000 square feet.

How many shingles are typically required for a square?

Typically, three bundles of shingles are required to cover a square, which is equivalent to 100 square feet.

How is the cost of shingles calculated per square?

The cost of shingles per square is calculated by multiplying the price of one bundle of shingles by the number of bundles required to cover a 100 square foot area, typically around three bundles.

How does the weight of a square of shingles affect the structural performance of a roof?

The weight of a square of shingles can significantly affect the structural performance of a roof by putting undue strain on the roof frame and potentially leading to sagging or other structural issues.