When it comes to roofing lingo, “squares” and “square feet” are terms that often get thrown around. But what exactly do they mean, and how many squares of shingles do you need to cover a 1200-square-foot roof? Let’s break it down in simple terms.

Understanding Shingle Squares

Before we dive into the calculations, let’s clarify what a “square” of shingles is. In roofing lingo, one square is equal to 100 square feet of roof area. It’s a convenient unit of measurement that simplifies the estimation process. Roofing materials, including shingles, are typically sold in squares, so understanding this concept is crucial.

Calculating Shingles for a 1200-Square-Foot Roof

Now, let’s figure out how many squares of shingles you’ll need for your 1200-square-foot roof. It’s a straightforward process:

Step 1: Calculate the Roof Area

To find out the total roof area in square feet, measure the length and width of your roof and multiply these dimensions. For example, if your roof is 30 feet long and 40 feet wide:

1200 square feet = 30 feet (length) × 40 feet (width)

Step 2: Convert to Squares

Since one square equals 100 square feet, divide the total roof area (in square feet) by 100 to get the number of squares needed:

1200 square feet ÷ 100 = 12 squares

So, you’ll need 12 squares of shingles to cover your 1200-square-foot roof.

Considerations and Variations

It’s important to note that the above calculation provides a basic estimate. Roofing may involve additional factors such as:

1. Overhangs: If your roof has significant overhangs or complex angles, you might need a bit more material to account for these areas.

2. Waste Factor: Roofing jobs often require a waste factor of around 10% to 15% to cover mistakes, cutting, and any future repairs. To be safe, consider adding an extra square or two to your estimate.

3. Shingle Type: Different types and brands of shingles have varying coverage areas per square. Check the product specifications to ensure you’re buying the right amount.

4. Roof Pitch: Steeper roofs may require additional materials due to the increased surface area.


In summary, to determine how many squares of shingles you need for a 1200-square-foot roof, you’ll calculate the roof’s square footage and then convert it to squares. Remember to account for any overhangs, waste, shingle type, and roof pitch to ensure you have enough materials for your roofing project.

It’s always a good practice to consult with a roofing professional or supplier for precise estimates tailored to your specific roof. With the right amount of shingles, you’ll be well on your way to completing a successful roofing job.


As a civil engineer and roofer, I love to share the experience that I have gained through the last couple of years. In the roofing industry, practical experience is a very crucial fact that can help you a lot. Hence, I want to help you with my blog.

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