Tyre size explained: What are all those numbers and letters?

So your tyres are looking a little worse for wear, and it may be time to switch them out. Not sure where to start? Car tyre size can be confusing, but if you want to score the right size set for your car, you need to know the basics of reading a tyre. That way, you’ll know just what tyres are the right size for your hatchback, sedan, SUV, 4WD—or whatever car you drive!

Let’s take a look at what you need to know to make finding that new set of tyres flat-out simple!

Car tyre size explained: what does tyre size mean?

A good first step to buying a tyre is knowing what ‘size’ actually refers to. Simply put, the tyre size is made up of three main components:

1. The width of the tyre when viewed from the front of the car

2. The profile of the tyre, which is the height of the tyre from the outer edge to the rim

3. The diameter of the rim

That’s the basis of your tyre size, meaning it’s all of the above put together.

How to find your tyre size

Ever wonder what all those numbers and letters mean on your tyres? Let’s take a look at the tyres already on your car. You can find the size you need by looking at the sidewall of the tyre. The first set of numbers in the sequence all refer to the size.

If you don’t have a set of tyres to look at, or just don’t want to get down to have a look, the recommended tyre size is usually also on a sticker or placard inside the driver’s side door for easy access. . You can also find it in your owner’s manual. So finding your tyre size is fairly easy, if you know where to look.

Or make it even easier by checking the mycar website, where you can search for tyres by rego or vehicle make, year, and model. It’s an easy way to do it, all from the comfort of your armchair!

How to read tyre size

Now you know where to look, you need to know how to read a tyre size, as it can look a bit like another language if you’re not sure! Don’t worry though, we’ve made it easy with an example below.

Say your tyre has the following numbers and letters on its sidewall:

215/60R16 95V

95V, or the numbers followed by a letter at the end, refers to the load index and speed rating of the tyre, so while they’re important, they don’t really relate to the tyre size.

So what about reading tyre size? How do those numbers translate?

Tyre size numbers explained

To get to the meaning of tyre size numbers, you need to understand what each one refers to.

Using our example again, 215/60R16 95V, 215 means that the tyre is 215mm wide from the inside to the outside edge across the tyre tread.

The profile, otherwise known as the aspect ratio, is 60 in our example. It’s measured as a percentage of the width, so in this case the height of the tyre is 60% of the tyre’s width when viewed from side-on. If you have low-profile tyres, this number would be lower.

The last number relating to size in our example is 16, which refers to the diameter of the rim in inches.

The last number is the load index, or the maximum weight it can carry in kilograms. You need to view a table to decipher this one. In our example it’s 95, which translates to a load index of 690kg per tyre.

What do tyre letters mean?

Going back to our example, 215/60R16 95V, there are two letters in there as well.

The first, which is R in our example, refers to the construction of the tyre.. In this case, it’s ‘radial’, which is pretty standard for passenger vehicles these days.

The last letter in our example is V, which represents a code for the maximum speed the tyre can withstand, as tested by the manufacturer. These letters are coded depending on the speed rating of the tyre, from 140 km/h up to 300 km/h. In this case it’s a V, which means it is rated to a maximum of 240 km per hour.

And that’s it. Now you know what to do when it comes to reading a tyre size!

Can I put a different tyre size on my car?

It’s important to stick with the tyre sizes for your car as recommended by the manufacturer. Always check the approved tyre sizes in the vehicle owner’s manual, and if you’re still not sure, chat to one of our expert tyre fitters.

Changing your tyre size outside of these recommendations can affect many things such as the speedometer and odometer accuracy, as well as potentially making your car less safe, or even unroadworthy.

If for any reason you are considering changing your tyre size, speak to an expert first.

How do I know what tyres will fit my car?

To find out which tyres fit your car, you’ll need to look at the sidewalls of the tyres on the vehicle, in your owner’s manual, or on the placard in the driver’s side door .

Makes and models will differ, so do your research or chat to your local mycar mechanic to find out what works for your car. You can always check out our helpful blog with a few popular cars and the tyres that fit them that’ll give you a good starting point!

mycar - all your tyre needs under one roof

Now you know how to read your tyre size, be sure to head to mycar for professional tyre fitting, wheel balancing, alignment and repairs. We also have a wide range of tyres to suit all kinds of vehicles. Our expert technicians are always here to answer your questions so don’t hesitate to call us on 13 13 28 today!