How Many Shingles Equals a Square? We Explain Exactly

Installing a new roof is a major project that requires careful planning and accurate materials estimation. One of the key calculations is determining how many shingles you need per square of roof area. This number can vary substantially depending on the type and size of shingle you choose.

Whether you're a DIYer or hiring a roofing contractor, a full understanding of shingles per square will ensure you don't underestimate your roofing needs. With the right information, you can avoid wasted time and money from ordering inadequate materials or paying for excess shingles you don't end up using.

What is a Square in Roofing?

In roofing, a square is defined as 100 square feet of roof area. It's the basic unit used to estimate the quantity of materials needed. One square equals an area 10 feet by 10 feet. To determine the total number of squares for your project, simply calculate the total square footage of your roof and divide by 100. This will give you the total squares you need to cover.

Why is a Square Unit Used?

The square unit became the standard for roofing calculations because it simplifies the math. Materials like shingles and underlayment are packaged and sold based on their coverage per square. By determining your roof's area in squares, you can easily calculate how many material bundles you need without complex fractions or conversions.

How Many Squares are on a Typical Roof?

The number of squares on a roof depends on the total footprint and pitch. On average, simple gable roofs have 15-30 squares of area. More complex roofs can reach 50-100 squares. Mansard or extremely steep roofs may require calculating each pitch section separately. Always double check your square measurements to determine an accurate shingle quantity.

Why Shingle Count Per Square Varies

Unlike other roofing materials sized by linear feet, shingles are sold in discrete bundles with set coverage per square. But shingle dimensions, thickness, and bundling can vary significantly between different products. This means the number of shingles making up a square changes based on the specific type you select.

Shingle Shape and Size

Traditional 3-tab shingles are relatively small in size - around 12" x 36". Larger dimensional or architectural shingles may be up to 14" x 40" or more. Larger shingles cover more area individually. So per square, you need fewer pieces compared to a smaller shingle. Shape also plays a role, with hexagonal, octagonal, and staggered edge designs affecting overlap and spacing.

Thickness Differences

Thicker shingles take up more space when stacked and bundled. For example, a heavier 0.5" synthetic slate shingle will come in a thinner bundle compared to 0.25" lightweight 3-tabs. Each slate shingle covers more area, resulting in a lower number needed per square.

Manufacturer Bundling

While shingle size determines potential coverage, manufacturers choose how to group and package shingles for sale. One may bundle 27 pieces while another bundles 33 in a stack. This bundling also determines pieces per square. Field testing yields the optimal bundles for full square coverage.

Number of 3-Tab Shingles Per Square

As one of the most affordable and used asphalt shingles, 3-tab shingles are a roofing standard. Their classic look comes from the distinctive three tabs on each piece. For a traditional layered asphalt shingle, 3-tabs run smaller in size.

Most 3-tab shingles are around 12" x 36", or just under 3 square feet each. They're bundled in stacks of 27 to 33 pieces. This equates to between 86-102 square feet of coverage on average. With 100 square feet per roofing square, you will need approximately 87 3-tab shingles per square installed.

Popular 3-Tab Brands and Bundling

• GAF Timberline - 27 shingles per bundle
• Owens Corning Oakridge - 33 per bundle
• CertainTeed XT25 - 33 per bundle

Always consult manufacturer specifications since 3-tab products vary. Regional climate and code standards may also affect required shingle weight and dimensions.

Architectural Shingle Squares

Architectural shingles, also called dimensional or laminated shingles, provide an upgraded aesthetic over 3-tabs. They have multiple layers and are thicker overall, with depth and texture to mimic wood shakes or slate tiles.

Being larger in size and thicker in construction, architectural shingles have different coverage rates. Popular products average between 12" x 36" to 14" x 40" per piece. Bundles contain approximately 22 pieces and cover around 20 square feet each.

With this bundling and size range, you will need between 57-66 architectural shingles to complete one square. The exact number depends on the specific product.

Common Architectural Brands and Bundling

• GAF Timberline HD - 22 shingles per bundle
• Owens Corning Duration - 21 per bundle
• Malarkey Legacy - 21 per bundle

Premium architectural shingles may have unique shapes or be heavier in weight. This further impacts the pieces needed per square. Consult manufacturer literature to determine a material requirement accurately.

Specialty Shingle Square Calculations

Beyond basic 3-tabs and laminated asphalt shingles, there are a number of specialty roofing shingles to consider:

Synthetic Slate

Synthetic or manufactured slate replicates the look and durability of natural stone slate roofing. Like real slate tiles, these composite shingles are installed piece-by-piece, not bundled. Coverage per square depends on the size format and required overlap between courses.

Metal Shingles

Steel, copper, and aluminum shingles offer unique architectural profiles. Like slate, metal pieces are installed individually, often in alternating overlap patterns. Measurements are needed per piece to determine total quantity for the roof.

Ceramic Tile and Cedar Shakes

For specialty roofs with ceramic or clay tile and cedar shakes, coverage rates cannot be bundled into squares. Each tile or shake needs to be counted by linear feet based on sizing. An additional 10% extra is added to compensate for cuts, breakage, and waste.

How to Calculate Shingles Needed

Let's walk through an example of calculating total shingles needed for a roofing project:

1. Measure roof area: 24 ft x 44 ft = 1,056 sq ft total
2. Divide by 100 sq ft per square: 1,056 sq ft / 100 = 10.56 squares
3. Round up squares: Use 11 squares
4. Pick shingle type: Timberline HD architectural shingles
5. Look up shingles per bundle: 22 pieces
6. Check square coverage: Approximately 20 sq ft
7. Divide squares by coverage: 11 squares / 20 sq ft per bundle = 5.5 bundles
8. Round up for waste factor: Purchase 6 bundles
9. Bundles x shingles per bundle: 6 x 22 = 132 shingles needed

Always round up your materials estimate and add at least 5% extra for waste and defects. It's far better to have leftovers than run short on a roofing project.

Why Proper Shingle Calulation Saves Time and Money

Taking the time to accurately determine shingles needed per square prevents wasted budget and delays. With careful math, you can:

• Avoid running out of shingles mid-job
• Prevent purchasing excess materials
• Save time with single shingle order and delivery
• Reduce landfill waste from unused shingles

Why Manufacturer Specs Matter

While we've provided general guidance on shingles per square, manufacturer literature will give you exact numbers for each product. Specification manuals indicate:

• Dimensions of each shingle
• Weight per piece
• Pieces per bundled stack
• Coverage area per bundle

Having these specs allows you to calculate squares accurately. It also helps you compare between shingle product lines and prices.

Keep in mind that manufacturers will sometimes update or change their product offerings. So always consult current documentation on the exact shingle model you're using for a project.

Field Testing Provides Real-World Coverage Rates

Manufacturers arrive at square coverage rates by testing shingles on actual roofs during R&D. This helps them determine optimal bundling and installation to minimize waste. The tested coverage rates account for real-world cutting, defects, and nailing needs.

Trust in the manufacturer testing. Their bundled square coverage rates have been refined over many field installations to be accurate. Use the figures specified to calculate squares with confidence.

If you're tackling a roofing project, accurate shingle quantity estimation helps ensure you order just the right amount of materials. While the number of shingles per square varies by product, you can determine exactly how many you need with a few measurements and calculations.

Using our guide, you can calculate individual requirements based on your specific roof's square footage and desired shingle type. Understanding the coverage math ahead of time gives you a major advantage. So follow our tips to determine and order the precise number of shingles your project needs.