When it comes time to replace your tyres, you’ll need to know how to read your tyre size. When shopping for tyres, you’ll find that there are hundreds of options to choose from. But not all tyres will fit your vehicle and using the wrong one can be dangerous. You’ll want to make sure you’re in the know. 

Where to find your tyre size

You can find the right tyre size for your vehicle by checking the owner's manual. Alternatively, the tyre size will be printed onto the side of your tyre on the area known as the sidewall.

Tyre size explained

On the side of your tyres, you’ll find a set of letters and numbers. This is the information you need to determine the size of your tyre.


Make sure to check each tyre as you may have different sized tyres on the front and back of your vehicle. 

What do these numbers mean?

The numbers on your tyre represent its width, profile (aspect ratio) and rim diameter.

For example, if the marking inside your tyre is 155/80R12 94Y, then...

The width is 155mm

The number before the slash is the width of your tyre in millimetres. This is measured across the widest point of your tyres. In this case, the tyre has a width of 155mm.

The profile is 80% of the width

The two-digit number that comes after the slash is your profile, also known as the aspect ratio. This number is a percentage of your tyre’s width and represents the depth of the sidewall (the sidewall is the wall at the side of your tyre). So, the tyre’s profile is 80% of its width, or 124mm.

The diameter of the rim is 12 inches

The next set of numbers is the rim. This is the diameter of the wheel that the tyre is designed to fit on. The rim is measured in inches. This tyre’s rim is 12 inches.

Wheel size vs tyre size

Tyres are designed to fit on your wheel rims. But not all tyres are designed to fit all rims, and vice versa. Rims are measured in inches, and are commonly available in 16, 17 and 18 inch sizes. Each car/tyre may come with different rim size options, so it’s important to check the size before upgrading your rims.

Need help?

Our team of tyre experts is ready to assist you in finding the perfect tyres for your vehicle. Give us a call today at 13 23 81 to receive personalised guidance and recommendations.

Alternatively, you can visit our website to locate the nearest store and explore our wide range of tyres