Published on January 16, 2023 by Jason Reisman

How To Measure a Roof for Shingles: A Brief Guide

If you want to try installing your own shingles or tackle roof replacements, you’ll need to learn some shingle roof basics, including how to measure a roof for shingles. That way, you’ll have a correct cost estimate and won’t overbuy or run out of materials while you work.

The following simple formula will let you know how many shingles you’ll need for your roof.

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Measuring a Gable Roof for Shingles

A safety not first: Measuring a roof surface usually involves working at heights, so make sure to secure your ladder and take no unnecessary risks. It’s also advisable to use fall-prevention equipment like a safety lifeline rope and a fall-arrest harness.

To calculate your roof’s square footage, you’ll need to identify and measure every roof plane separately. The simplest gable roof structure includes two rectangular planes.

You should:

  1. Measure the length and width of each plane with a measuring tape.
  2. Write down every individual plane’s measurement
  3. Calculate the square footage of each plane according to its shape (rectangle or square, trapezoid, triangle, etc.)
  4. Add up all planes’ area to find out your roof’s total square footage


Translating Square Feet Into the Number of Shingles You’ll Need

The next step in “how to measure a roof for shingles” is determining how many shingles you’ll need for your roof’s square footage.

Once you’ve calculated your roof’s area and determined the number of roofing squares, you can select high-quality shingles like CertainTeed’s SwiftStart to ensure a durable and aesthetically pleasing roofing solution.

A standard shingle bundle usually covers around one-third of a roofing square. Thus, you’ll need about three shingle bundles per square, or 45 bundles for a 15-square roof.

To make sure you don’t run out of shingles, add an extra 15% to account for waste that occurs in every roofing project. For instance, if you’ve determined you need 45 shingle bundles, multiply that number by 1.15 and you’ll get 51.75, which you’ll round up to 52 bundles.

Should You Install or Replace Your Own Shingles?

Even if you take every safety precaution, shingle installation or replacement involves risks, especially if you have an especially high roof pitch or roof areas with poor access.

Hiring a professional for your roof job ensures that you’ll get a top-performing, durable roof that will stand the test of time and weather. A competent contractor will also minimize any chance of accidental damage to your roof system.


Eustis Roofing: Trusted Roofing Services in Tavares, FL, Since 1959

At Eustis Roofing, we have been providing quality shingle roof installation, repair, and replacement services to Lake County, FL, since 1959. When you work with us, you don’t need to ask “How to measure a roof for shingles?”—our experienced team will provide you with a precise cost and materials estimate.

Whether you choose architectural shingles, metal roofing, or a specialty roof, we are your reliable local roof contractor. Call us at (352) 343-4240 or contact us online for a free roofing quote in the area of Summerfield, FL. 

Jason Reisman

About The Author: Jason Reisman

Jason Reisman, ERC’s General Manager is a problem solver! Jason is hands-on with finding solutions to difficult problems as well as constantly researching, exploring new concepts, discovering new inventive ways and is passionate about being the most experienced, most knowledgeable and most dependable in the roofing trade. He’s hands-on with training and instruction ensuring every job have the up to date and state of the art equipment to perform with precision to be in and out without delays. Jason loves competing with his Dad on the golf course!