How do I find my tire size?

One of the most important things to know when choosing new tires is how to determine the right tire size for your vehicle. Determining the right tire size can be done in a number of ways. If you already have the vehicle, and are wondering how to find the correct tire size, it can be as simple as taking a look on the sidewall of your current tires, and writing down the series of numbers and letters printed on the tire.

Your group of numbers and letters may look something like this – P235/65R17 108T, and this grouping is also called the tire’s size code. (Your numbers may be different). So if you are wondering, “Where do I find the tire size?” in this group of numbers, the three-digit number directly after the first letter is your tire size. This grouping of three numbers is the tire width in millimeters measured at its widest part, and may also be called the section width.

Immediately following the three-digit number is a two-digit number, which is the tire’s aspect ratio, or, more simply, it is the height or profile of the tire’s sidewall expressed as a percentage of the tire’s width. Because tires come in many different sizes, you want to make sure you have both these numbers when tire shopping to ensure you choose the right tire size.

Rim size is also important, and this information can be found after the aspect ratio number – for example, R17. The number after the R is the rim size of your tire, and you also need to know this information when buying new tires.

Then, the last part of understanding your tire size is knowing the speed rating of your tire. The speed rating is expressed as a letter – like the T in our example above. To understand how this letter represents a speed rating, you can look up the associated km/hour number. The speed rating for T is 190 km/h or 118 miles per hour. This is the maximum speed that these tires should be operated at – and anything over that speed could mean your tires won’t operate at their optimal performance, and safety could become an issue.

No tires to look at? There are other ways to find out your tire size, even if you don’t have the old tires in front of you. You can look inside your vehicle’s owner manual to find out, and sometimes there is also a listing of your tire size on a sticker in the inside of your car door, or inside the gas tank hatch.

Our team at is 100 per cent committed to ensuring your total satisfaction in your tire purchase with us. If you have any questions regarding any of the brands that we sell, or questions regarding the best kinds of tires for your vehicle and budget, then we encourage you to reach out to us by telephone, email or by chatting with an online representative. We are completely committed to your satisfaction in your tire purchase with us.