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How to Calculate Roof Pitch

The steepness of your roof determines how effectively it can slough off moisture from snow and rain. You’ll want to know the pitch of your roof if you’re deciding the appropriate roofing materials to use on your home. Learning how to calculate roof pitch is simple, effective, and it only requires a couple tools.

How to Calculate Roof Pitch:

  1. You can measure roof pitch from inside the attic or from the outside of your house. This article will explain how to measure the roof pitch from inside, which is the easiest and safest way to do it.
  2. Draw a dark line on the 12-inch mark of your carpenter’s level using a sharpie or marker.
  3. Hold the carpenter’s level horizontally, making sure the bubble is exactly in the middle and that the level is plumb.
  4. Measure from the top of the carpenter’s level to the top of the rafter. That’s your roof pitch.
  5. A helpful tip? There’s also a roof pitch and slope calculator that you can purchase. A simple manual calculator costs less than ten dollars and you can pick one up at your local hardware store or order it online.

How to Talk About Roof Pitch

People often talk about roof pitch by telling you the rise over the run. The rise, which is the first number, tells you how tall the roof is along the vertical line. The run, which is the second number, is always expressed as 12 inches. If someone tells you their roof’s pitch is 5:12, then they are saying their roof rises 5 inches for every 12 inches of horizontal run. A standard pitched roof generally ranges from 4 to 8 inches for every 12-inch run.

If the first number is 9 inches or higher, it’s a steep roof and requires the use of significant safety equipment for roofers to work on it. When the roof pitch is lower than 4 inches, it’s considered a low-pitch roof and requires different roofing materials.

Tools & Materials

  • Standard 18 or 24-inch carpenter’s level
  • A steel tape measure
  • A sharpie or pen

Hire Local Home Remodeling Professionals

Maybe you’re thinking about doing a home renovation or re-roofing your home. Have you ever considered hiring professionals to help with the hard work? At PJ Fitzpatrick, we’ve been helping people with home remodels, home maintenance, and renovations since 1980. Our roofing experts can show you how to calculate roof pitch or provide you with an estimate to repair or replace your roof. Request an estimate today and we’re happy to answer any questions you may about your roofing project.

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