TL;DR:
A roofing square equals 100 square feet of roof area. Most standard 3-tab asphalt shingles require three bundles to cover one square, while architectural shingles typically need four bundles per square. Premium or specialty shingles may require even more bundles to fill a roofing square due to their thickness and design.
Understanding Roofing Measurements: Squares and Bundles
When planning a roof replacement or repair, understanding how roofing materials are measured is essential for your project’s success. In the roofing industry, measurements aren’t always what they seem at first glance.
A “square” in roofing terms doesn’t refer to a shape but rather to a specific unit of measurement. One roof square is equal to 100 square feet of roof area. This standardized measurement helps simplify calculations when determining how many shingles you’ll need for your roof.
Shingles are sold by the bundle and by the square. A bundle of shingles contains a specific quantity of shingles that, when installed, covers a portion of a roof square. The number of shingles in a bundle can vary by manufacturer and shingle type, but they’re packaged to make transportation and handling manageable since roofing material can be quite heavy.
How Many Bundles of Shingles Make a Square?
The number of bundles needed to cover one square of roof depends primarily on the type of shingle you’re using:
Standard 3-Tab Shingles
For traditional 3-tab asphalt shingles, it typically takes three bundles to fill a roofing square. Each bundle covers about 33.3 square feet, so three bundles will cover the required 100 square feet of roof area.
Architectural Shingles
Architectural shingles (also called dimensional or laminated shingles) are thicker and heavier than standard shingles. Because of this increased thickness, you’ll generally need more bundles per square. Most architectural shingles require four bundles to cover a square, though some higher-end architectural shingles may take 4-5 bundles per square due to their substantial profile.
Premium and Specialty Shingles
Premium shingles, designed to mimic slate or wood shake appearances, often require even more material per square footage. These specialty shingles may need up to five or even six bundles to fill a roofing square, depending on their design and thickness.
Understanding these differences is crucial when calculating the number of bundles needed for your roofing project. Using the wrong estimate could leave you short on materials or with excess shingles.
Calculating Shingle Bundles for Your Roof
To calculate how many bundles of shingles you’ll need for your roof, follow these steps:
- Measure your total roof area in square feet.
- Divide this number by 100 to convert to roofing squares.
- Multiply by the number of bundles per square required for your chosen shingle type.
For example, if your roof is 2,000 square feet and you’re using standard 3-tab shingles (three bundles per square):
- 2,000 ÷ 100 = 20 squares
- 20 squares × 3 bundles = 60 bundles needed
It’s important to note that your home’s square footage isn’t the same as your roof area. The roof area is typically larger than the building’s footprint due to overhangs, multiple stories, and roof pitch.
For complex roof designs with multiple planes, dormers, or steep pitches, you’ll need to calculate each section separately and then add them together. Many roofing contractors recommend adding 10-15% extra shingles to account for waste, cuts, and starter strips.
Shingle Bundle Variations by Brand and Type
Different manufacturers may package their shingles per differently, which can affect how many bundles are needed to cover a square. Here’s how some common types compare:
Standard Asphalt Shingles
Most standard asphalt shingle bundles cover approximately 33 square feet, requiring three bundles to a square. These are the most common roof shingles used in residential construction.
Architectural Shingles
Architectural shingles typically cover about 25 square feet per bundle, requiring four bundles per square. These shingles create a more dimensional appearance and often have longer warranties than standard shingles.
Premium Designer Shingles
Premium shingles often cover even less area per bundle, sometimes needing five bundles to cover one square of roof. These specialty shingles offer unique aesthetic benefits but require more material.
The weight per bundle also varies significantly. A bundle of standard shingles may weigh 60-80 pounds, while architectural shingles can weigh 70-90 pounds per bundle. This weight difference is important to consider for structural concerns and for transportation purposes.
Factors Affecting How Many Bundles of Shingles You Need
Several factors can influence the amount of shingles you’ll need for your roof:
Roof Complexity
Complex roofs with multiple angles, valleys, and dormers require more shingles due to the additional cutting and waste generated during installation.
Roof Pitch
Steeper roofs have more surface area than flat roofs with the same footprint. A roof with a steep pitch may require more shingles to cover the increased square footage.
Starter Strips
Don’t forget that most roofing projects require starter strips along the eaves and sometimes rakes. These are additional shingles that need to be factored into your total.
Ridge Caps
Ridge caps are specialized shingles needed to cover the peaks where roof planes meet. These are typically sold separately and are not included in standard bundle calculations.
Practical Example: Calculating Bundles for a Typical Home
Let’s work through an example to determine how many bundles are needed for a common roof size:
For a 1,800 square foot ranch-style home with a moderate pitch, the actual roof area might be approximately 2,000 square feet or 20 roofing squares.
If you’re installing standard 3-tab shingles:
- 20 squares × 3 bundles per square = 60 bundles
If you’re upgrading to architectural shingles:
- 20 squares × 4 bundles per square = 80 bundles
And if you’re choosing premium laminated shingles:
- 20 squares × 5 bundles per square = 100 bundles
Additionally, you’ll need to account for starter shingles, ridge caps, and waste. A good rule of thumb is to add an extra 10-15% to your total, especially for complex roof designs.
Buying the Right Amount of Shingles for Your Roofing Project
When purchasing shingles for your roof, it’s always better to buy slightly more than your exact calculation suggests. Running short during a roofing project can lead to delays and potential color matching issues if you need to purchase additional bundles later.
Most suppliers will allow you to return unused, unopened bundles of shingles, so there’s little downside to having a small surplus. However, always check the return policy before making your purchase.
It’s also wise to keep a few extra shingles after your project is complete. Storing these for future repairs ensures you’ll have perfectly matched roofing material if you need to replace damaged shingles later.
Special Considerations for Different Roof Types
Different roof designs may require special consideration when calculating how many shingles you’ll need:
Hip Roofs
Hip roofs have more ridges than gable roofs, requiring more ridge caps and potentially more waste from cutting.
Dormers and Skylights
Features like dormers and skylights create additional angles and joints, increasing the amount of waste generated from cutting shingles to fit these areas.
Mansard Roofs
Mansard roofs have very steep sides that are almost vertical. These sections require significantly more shingles than a standard pitched roof of the same square footage.
FAQs About Shingle Bundles and Squares
How many shingles are in a bundle?
The exact number of shingles depends on the type and manufacturer, but a typical bundle of 3-tab shingles contains around 26-29 individual shingles, while architectural shingles may have 21-26 per bundle.
What’s the difference between 3-tab and architectural shingles?
3-tab shingles are flat, single-layer shingles with three tabs per strip, while architectural shingles are multi-layered with a dimensional appearance that often mimics wood or slate. Architectural shingles are typically heavier and more durable but require more bundles per square.
Do I need to buy ridge caps separately?
Yes, ridge caps are usually sold separately from regular shingles. They’re specially designed to bend over the ridge while providing proper coverage and weather protection.
How do I know how many bundles of starter shingles I need?
Measure the linear footage of all eaves (and sometimes rakes) where starter strips will be installed. One bundle of starter shingles typically covers 100-120 linear feet.
Can I mix different bundles of shingles on my roof?
It’s best to use shingles from the same production lot to ensure color consistency. If you must use shingles from different lots, try to use them on different sides of the roof to minimize noticeable color variations.
How long can I store extra bundles of shingles?
Properly stored shingles can last for years. Keep them in a dry, flat location away from extreme temperatures. This ensures you’ll have matching materials for future repairs.
By understanding how many bundles of shingles you need for your specific roof and shingle type, you can properly budget and plan for your roofing project. Remember that investing in quality shingles and proper installation will extend the life of your roof and protect your home for years to come.