How Many Roofing Shingles Do I Need?

If you’re getting ready to fix or replace your roof, you’ll need to know how many roofing shingles to buy. Taking the time to measure and plan will help you save money and avoid headaches during your project. This guide will walk you through every step, using easy words and helpful tips.

What Are Roofing Shingles?

Roofing shingles are the flat, overlapping pieces that cover your roof. They protect your home from rain, wind, and sun. Most people use asphalt shingles because they are affordable, strong, and easy to install. There are also other types of roofs, like metal or wood, but asphalt is the most common for homes.

Importance of Calculating Shingles Correctly

Buying just the right amount of roofing shingles is important for a few reasons:

Saves Money: You don’t want to buy too much or too little.
Avoids Delays: Running out of shingles can stop your project.
Better Results: Having enough shingles means your roof will look good and last longer.

How to Measure Your Roof?

Before you order shingles, you need to know how big your roof is. Here’s how you can measure it:

Step 1: Draw Your Roof

Draw a simple picture of your roof from above. Split it into rectangles and triangles if your roof has different shapes.

Step 2: Measure Each Section

For rectangles: Measure the length and width of each section.
For triangles: Measure the base and the height.

Step 3: Find the Area

Rectangles: Multiply length by width.
Triangles: Use the formula: (base × height) ÷ 2.

Step 4: Add Them Up

Add the area of all sections to get your total roof area in square feet.

Example:
If you have a main roof (30 feet by 40 feet = 1,200 sq. ft.) and a garage roof (20 feet by 15 feet = 300 sq. ft.), your total is 1,500 sq. ft.

How to Calculate the Number of Shingles Needed?

Now that you know your roof’s size, you can figure out how many shingles to buy.

Roofing Square

A “roofing square” is a term used in roofing. It means 100 square feet of roof.

Step 1: Find the Number of Squares

Divide your total roof area by 100.

Example:
1,500 sq. ft. ÷ 100 = 15 squares.

Step 2: Find the Number of Bundles

Most shingles come in bundles. Usually, you need three bundles to cover one roofing square.

Example:
15 squares × 3 = 45 bundles.

Adding Extra for Waste and Tricky Roof Parts

Roofs are never perfectly simple. You’ll need extra shingles for:

Cutting around chimneys, vents, and skylights
Starting rows at the edges
Waste from mistakes or bad cuts

Add 10–15% extra to your total bundles.

Example:
45 bundles × 1.15 = 51.75 bundles (round up to 52 bundles).

If your roof is very complicated (lots of angles, valleys, or steep parts), you might need even more extra.

Things That Affect How Many Shingles You Need

Some things mean you’ll need more shingles:

Steep slopes: The steeper your roof, the more shingles you’ll need.
Lots of angles or features: Chimneys, skylights, and valleys mean more cutting and waste.
Type of shingles: Some shingles cover less area per bundle, so always check the label.

Tools and Help for Figuring Out Shingles

If you’re not sure about your measurements, you can use:

Online calculators: Many websites have tools to help you calculate the shingles needed.
Professional help: If your roof is tricky, it’s best to ask a roofing expert for help.

Sometimes, you might need Shingle Roof Repair Services if your roof is damaged but doesn’t need a full replacement. If your roof is old or badly damaged, you might need a Roof Replacement Service. Regular Roof Inspections in Atlanta or your area can help you catch problems early.

Tips for Ordering Shingles

Here are some easy tips for ordering your shingles:

Buy extra: Always get a little more than you think you need.
Check the label: Make sure you know how much area each bundle covers.
Store them safely: Keep shingles in a dry place until you’re ready to use them.

Common Mistakes to Avoid

Here are some mistakes people make when ordering shingles:

Forgetting to measure all parts of the roof
Not adding extra for waste
Not checking how much area each bundle covers
Forgetting to buy starter shingles for the edges

When to Ask for Professional Help

If your roof is complicated or you’re not sure about your measurements, it’s best to ask a roofing professional. They can help you:

Measure your roof correctly
Calculate how many shingles you need
Handle tricky parts like valleys and chimneys

Why It’s Important to Get the Right Amount

Getting the right number of roofing shingles is important because:

You save money by not buying too much
You avoid running out of shingles in the middle of the job
Your roof will look better and last longer

Final Thoughts

Figuring out how many roofing shingles you need might sound complicated, but it’s just a matter of careful measuring and planning. By following the steps in this guide, you’ll be able to buy the right amount of shingles and avoid common mistakes.

Remember, if your roof is tricky or you’re not sure about your measurements, it’s always best to ask for help from a roofing professional. They can help you get accurate numbers and make sure your roof is done right.

Whether you’re doing a small repair, a big replacement, or just want to keep your roof in good shape, knowing how to calculate your roofing shingles is a valuable skill. It will save you time, money, and stress—and help keep your home safe and dry for years to come.