How to read your tyre size from your tyre sidewall

UNDERSTANDING TYRE MARKINGS

How to Read Your Tyre Size

Most tyre sizes are printed clearly on the sidewall. Once you know what each number and letter means, the code is straightforward to understand.

Example: 175/65 R14 82T

Each part of this example tyre size tells you something different about the tyre.

175Tyre width

The nominal tyre width in millimetres.

65Aspect ratio

The sidewall height expressed as a percentage of the tyre width.

RConstruction

R means radial construction, used by the vast majority of modern road tyres.

14Wheel diameter

The rim diameter in inches that the tyre is designed to fit.

82Load index

The tyre’s load-capacity code. Use our load rating chart to convert the number.

TSpeed rating

The tyre’s speed-rating code. Use our speed rating chart for the corresponding value.

So the complete example is: 175/65 R14 82T. When asking us for a replacement tyre, giving us this full size plus your vehicle registration helps us identify the correct option.

What Size Wheel Trim or Alloy Wheel Do I Need?

The wheel diameter is the number immediately after the construction letter. In the example above, R14 means the tyre fits a 14-inch wheel, so a compatible wheel trim would also be 14 inches. Alloy-wheel compatibility involves additional measurements such as width, offset, bolt pattern and centre bore, so wheel diameter alone is not enough when choosing replacement alloys.

Important: Do not choose a tyre based on size alone. The correct load index, speed rating, vehicle approval and any manufacturer-specific requirements must also be considered.

Need Help Finding Your Tyre Size?

Call or message us with your vehicle registration and, if possible, a photo of the tyre sidewall.