Below is an example of a set of numbers that are displayed on the side wall of a tyre.
The first number, in this case 205, is the width of the tyre in millimetres, so 205mm wide.
The second number is the height of the tyre and is a percentage of the first number.
In this case 40, so 40% of 205mm. This number is also known as the profile.
The third number is the size of wheel it will fit in inches, in this case 16'.
The width of the alloy is measured from the inner rear lip to the inner front lip and is stated in inches.
Tyre sizes for the width of your alloys.