Can you tell us your tyre sizes? If you’re unsure, Trade Tyres have put together a quick and simple guide that’ll help you to understand what replacement tyre your vehicle requires.  

Tyre Size

On the sidewall of your tyre, you will find a combination of numbers and letters. Commonly across the UK, tyres will read 205/55R16, however, there are multiple variations, so if these codes don’t ring a bell, check your current tyres.

If you have your vehicle’s handbook ready, you can refer to this to find out your tyre size. It’s always important to know your tyres size before getting a replacement to ensure you’re up and running on the right wheels and to save you time and money. 

Tyre Width

Check out the first three digits on the tyre, this refers to the width of your tyre in the measurement of millimetres. If your tyre is marked as 225, this is reading that your tyre is 225 millimetres across the tread, measuring from one side of the sidewall to the other. 

Aspect Ratio

The following fourth and fifth digits marked on the tyre refers to the tyre’s width. The profile height or ‘aspect ratio’ of the sidewall of the tyre is referenced as a percentage of the tyre width. For example, if the following numbers of the code read ‘50’, this means that the tyre’s height is 50% of the tyre width. 

Radial

If you have radial tyres, they will be marked with the letter R. Radial tyres are made with cord plies, which are positioned at 90 degrees towards the direction of travel – this provides the vehicles’ tyre with additional strength. Nearly every new tyre made today will be a ‘radial tyre’. If you don’t see this, don’t worry, chances are your new replacement tyre will be a radial. 

Wheel Diameter

The last two digits marked on the tyre refer to the size of the wheel’s rim. This also represents the diameter of the tyre from one bead to the other. A tyre with the last two digits of 17 will be suitable for a 17-inch wheel rim.