When it comes to vehicle maintenance, tyres play an essential role. After all, they are the
only point of contact between your vehicle and the road. To ensure their proper functioning,
you must invest in the right tyres, and that means understanding how to read their size.
As a tyre user, reading the tyre size is just as important as choosing the right one for your
vehicle. In this blog post, we’ll go through the process of reading and understanding your
Tyre sizes are usually made up of a sequence of numbers and letters that are moulded onto
the sidewalls of the tyres. The sizing system includes three components – width, aspect
ratio, and rim size. The first set of numbers on the tyre always refers to the tyre’s width,
measured in millimetres from sidewall to sidewall.
For instance, if the number reads 205, your tyre’s width measures 205 mm.
The second number represents the aspect ratio, which is the percentage of the tyre’s width
that represents the sidewall’s height. For example, if this number is ’55,’ it means that the
height of the tyre is 55% of the width.
This number directly affects the tyre’s performance as it indicates how much flex and cushioning the tyre has.
The third number is the rim diameter size, usually measured in inches (but can also be in
millimetres). To know the tyre size needed, look for the rim diameter size in your vehicle
owner’s manual or check the tyre placard. For instance, if the number is ’17,’ it means that
the tyre fits 17-inch rim wheels.
Aside from the standard measurements, some tyres feature additional information. For
instance, the letter ‘R’ indicates the tyre’s internal components and has no effect on size. A
zero in the size indicates it is a Euro-metric tyre, while ‘LT’ or ‘C’ are used for light truck tyres.
Lastly, take note that not all tyres have the same size; some vehicles have different tyre
sizes on the front and the back. Ensure you make a visual inspection of the tyre sidewall to
determine the correct size for your vehicle.
Knowing how to read your tyre size is essential for ensuring that you select the right tyre for
your vehicle, and that you replace worn tyres with the correct fit. By following the steps
above, you have the necessary knowledge that can help you find the perfect tyre that
guarantees you a comfortable, safe and enjoyable driving experience.
Remember, you can always consult with a professional or refer to online guides for more
guidance on selecting the right tyre size for your vehicle.