Here’s Exactly How to Find Your Correct Tire Size

Here’s Exactly How to Find Your Correct Tire Size

So it’s time to get new tires, but you aren’t sure how to find out the tire size you need? Car ownership comes with the need to learn new things and knowing how to figure out your tire size is one of the basics. 

Finding your tire size can be tricky at first if you don’t know what you’re looking at, but once you know where to look it’s not too hard. You might need to provide this information when buying new tires, so it’s essential to understand how to locate it and what each of the numbers and letters mean.

How to find your tire size

Finding your tire size is pretty easy once you know what you’re looking for. There are actually a few different ways to do it, but the most common is on the side of the tire. Below you’ll find out where to find your tire size and what all of the codes mean.

On the tire

When looking at the side of your tire, you should see a series of letters and numbers along the sidewall. These codes indicate tire type, width, aspect ratio, construction, wheel diameter, load index, and speed rating. 

We’ll outline the different codes below in the order you should see them on your tire.

Example of what you may see:

P 265/65 R16 86S

Tire Type

The first letter will indicate the type of tire your car has. “P” is for passenger metric. There are other letters such as “LT” (light truck), “T” (temporary spare), and “ST” (special trailers). 

If the codes on your tire don’t start with a letter, that means that they are in Euro (metric) size. The only difference will be that they may have slight differences in load capacity and inflation pressure recommendations.

Tire Width

This next number represents the tire width represented in millimeters. When you measure the tire’s width at the widest point, you will get this number. In our example, this is the “265” number.

Aspect Ratio

The aspect ratio indicates the sidewall height. This measurement is a percentage of the width. So the number “65” in our example means that the tire’s sidewall height is 65% of its width. Lower numbers indicate a smaller sidewall height and are usually found on cars that are performance-based because it makes for better handling.


The next letter, “R” in our example, represents the tire’s internal construction. The “R” stands for radial and almost every tire is made this way. Radial means that the layers of the tire radiate across the tire from one side to the other. Other letters you may see are “D” (diagonal construction) and “B” (belted), but these are much less common.

Load Index/Rating

The last number indicates how much weight it can safely carry when inflated. Our example, “86”, indicates that it can carry a load of 1,168lbs. The higher the number, the higher load carrying capacity that the tire has. You can find a load index chart here.

Speed Rating

The very last letter represents the maximum safe speed the tires can carry. The letter in our example is “S”, which represents 112 miles per hour. They range from “A” to “Y” with higher speeds the further into the alphabet you go. The only exception “H”, which fits between “U” and “V”.


Other places you can find your tire size

Even though most people will simply look at their current tires to get the correct size, there are a few other places to find your tire size that originally came from the manufacturer. 

The first place is the car manual. You should be able to find a section that gives you the recommended tire size. 

Alternatively, many cars have a sticker inside the driver side door that can only be seen when the door is open. This sticker will also provide the recommended tire size. Since these are manufacturer recommendations, this may or may not be accurate if your tire size was changed when they were initially changed.

While it’s always nice to know your own way around your vehicle, you can always count on Jack Williams to help you with sizing your tires. We always make sure we outfit your vehicle with correctly sized tires. Contact us today and we will assist you with all of your tire service needs! 

January 15, 2021
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