How to Measure A Tire – Easy Guide

It is critical to know the tire size you are using. Whether you want a vehicle tire, motorbike tire, or wheelbarrow tire.

With the information on tire size, you will choose one for a smooth and safe ride. Therefore, you must adopt a safe way to measure all your tires.

In this article, you will learn all the vital steps and procedures on how to determine the tire size.

Let’s dive right in:

Step 1: Understand Tire Size and Dimension

Tire Dimensions
Tire Dimensions

Even though you would like to determine the tire size, every tire has some information written on it. In most cases, the tire manufacturer will give all vital details about the tire.

Although there are different formats, the most common way especially for vehicle tires may take this format:  P205/55R16 91 S

This implies:

  • P – It refers to the vehicle type
  • 205 – Refers to the tire width in mm
  • 55 – Ratio between the height of the tire and width. Normally, we refer to this as the aspect ratio
  • R – It is the radial construction of the tire
  • 16 – It is the diameter of the wheel in inches/RIM diameter
  • 91 – This is the loading index
  • S – Refers to the speed rating

Remember, there exist other parameters on the tire. Again the numbering above may vary from one tire to another. For instance, the example we have above is for vehicle tires. You cannot expect the same for say wheelbarrow tires.

Furthermore, you cannot measure certain variables indicated above. For example, you cannot determine vehicle type or rated speed.

Therefore, even as you measure the tire size and dimensions, this information gives an overview of the tire. That is, with this information alone, you will know the exact size of the tire.

Step 2: Have Tools you need for Measuring a Tire

Measuring tire size and dimensions does not require specialized tools or equipment. The process requires basic measuring tools such as:

  • Tape measure – its flexibility makes measuring tire circumference easier. Besides, you can determine the diameter, sidewall size, etc.
  • Depth gauge – It is a special tool for determining the tread depth. You can use a depth gauge to determine if the tires have recommended tread depth.

Step 3: Measure Tire Dimensions or Size

Use tape measure to determine tire dimension
Use a tape measure to determine tire dimension

Once you have all the necessary tools and equipment, it is now time to commence the process:

  1. First, you should take note of the dimensions printed on the tire. Your work here will only to verify whether the information available is accurate or not. Of course, at this point, you must identify the tire you wish to measure.
  2. Second, you should measure the tire width. That is, with one end of the tape measure on the outer edge of the tire, extend your tape measure to the opposite side. This measurement will be in millimeters.
  3. Third, measure the tire aspect ratio. That is, you will first measure the tire sidewall. You will then calculate this as a percentage of the width of your tire. If you wish to get the tire’s height, you will multiply the width of the tire and the aspect ratio percentage.
  4. Lastly, measure the diameter of the rim. Once you identify the center of the wheel, you will put the tape measure, then stretch across the opposite side.

As you can see, the process is quite straightforward. Remember, the process remains the same for virtually all types of tires.

For instance, if you want to measure wheelbarrow tires, start by determining:

  • Outside diameter
  • Then measure the length of the hub
  • Finally, determine the size of the bearing.

Remember, knowing your tire dimensions will help you get a good replacement. Besides, choosing the right tire size will ensure safety and better performance.

More Resources:

Tires Manufacturing Process – Source: KARMAN

How to Measure Tires – Source: Wiki How

One Stop Solution Wheels & Tires Manufacturing

Update cookies preferences
Scroll to Top