How to Measure a Mountain Bike Frame: Easiest Way to Do

When you want to walk fast and smoothly, the most important thing you need is a pair of shoes that are perfect in size. The same thing goes for biking. It is totally impossible to ride peacefully without a perfect sized mountain bike. You need to know which size is suitable for you. Otherwise, you can be seen in a discomforting look while biking. So knowing the measurements of your bike, especially the measurement of the frame of your mountain bike is required for you. Because the ultimate size of the mountain bike depends on the size of its frame. And now the question is how to measure a mountain bike frame?

We have designed this blog especially for you to let you know how to measure the frame of your bike. So let’s dig into the blog.

How You Can Measure a Mountain Bike Frame

In order to learn the method of measuring the frame of your mountain bike, first of all, you need to learn the parts of your mountain bike that are related to the part of the frame of the bike. 

The most important part of the frame that is used for the measurement of the frame is the seat tube. The seat tube is the vertical part of the triangle of the mountain bike that the frames form. This seat tube runs from the bottom of the saddle or seat post and meets the crank of the bottom bracket.


Basically, we use the C-T method to measure the frame size. C-T stands for “center of top”. This length of the seat tube is calculated from the middle of the bottom bracket to the top of the seat tube.

You can measure the frame easily by following the instructions given below:-

  1. First, you need to find out the top of the seat tube. The place where the seat clamp holds the saddle is the seat tube of the mountain bike. (Saddle means the seat of an MTB)
  2. Identify the center of the bottom bracket of your MTB. It is the place where the axle holds the crank arms together.
  3. Now you need a measuring tape for this step. Measure the distance between the starting point of the seat tube and the center of the bottom bracket very carefully. So now, you know the length of your seat tube. This is the C-T of your mountain bike.
  4. Record the measurement you got. You need to have the measurement in inches.

Size of the frames of mountain bike

Generally, we have 3 sizes of frames on mountain bikes. These are 17″, 19″ and 22″. We call them size S for small, some M for middle and size L for large. And there is another section of the extra-large frame for much taller people.

Are you in a plan to buy a mountain bike for you? Check the review of the best mountain bikes of 2020.


In this blog, we have tried to help you know the measuring method of a mountain bike frame in a nutshell. Hope that you will find this article helpful for you. If you wish to know the measuring methods practically then watch the video on measuring the mountain bike’s frame.

If you have any query or you have any opinion on our article please leave your words in the comment section.

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