Learning Center / How to Decode Tire Sizes


Choosing the right tire all depends on the tire size. On the sidewall of your tire, you’ll find a code that tells you the tire’s size and capabilities. However, many people do not choose the correct tire size because they do not understand the basics of the code. At TreadHunter, we are experts at finding the tire size that best fits your vehicle. Below is our helpful guide on how to decode tire sizes, so you get the best fit.

Understanding What’s on Your Tire Sidewall

The alphanumeric code on your tire’s sidewall is easy to understand once you know the meaning of the letters and numbers involved. The numbers are indicators of the size, type and performance of the tire. Here is an example of what the code looks like on your tire: P195/60R16 92H. Below, we break down the meaning of each letter and number.

● Tire Type

The letter starting off the code indicates what type of tire it is. The letter “P” at the beginning of this code shows that it is a P-Metric tire, indicating that it is intended for passenger cars. Most tire size codes begin with the letter “P,” but there are some instances where you will see the letters “LT.” The letters “LT” stand for light truck and can be found at the beginning or the end of the tire size. This type of tire usually requires higher inflation pressures than passenger tires. You can consult your vehicle’s manual or tire placard for the recommended tire size and inflation pressure.

● Tire Width

The first three-digit number refers to tire width. It is the width of the tire across the tread in millimeters. For example, the tire width is 195 millimeters for this tire.

● Aspect Ratio

The two-digit number after the slash mark in the code is referred to as the aspect ratio. This is the ratio of the height of the sidewall, compared to its width. The 60 in this example code means that the height is equal to 60% of the tire’s width. The bigger the aspect ratio, the bigger the tire’s sidewall will be.

● Radial Construction

The letter “R” in the code stands for radial, meaning that the layers run radially across the tire.

● Wheel Diameter

The wheel diameter is the size of the wheel measured from one end to the other in inches. The diameter indicates the size of the wheel that the tire is meant to fit. For example, a size P195/60R16 92H tire is made for a wheel with a 16-inch diameter.

● Load Rating

The load index stands for the maximum load that the tire can support when correctly inflated. The maximum load for this example tire size is 92.

● Speed Rating

This tells you the maximum speed capability of a tire. A tire with an H-speed rating has a maximum speed capability of 130 mph or 210 km/h. Generally, speed ratings are matched to the highest speed capability of the vehicle.

Find Your Tire Size

Now that you know how to decode your tire size, you can find the right tires for your vehicle online at TreadHunter. You can conveniently search by tire size, tire brand, wheel size, location and by the type of car you have all in the comfort of your home. Sign up online today or contact us for more information.