The first number in a tire size represents the nominal width (usually in millimeters). Width is measured in a
straight line from the furthest point on one sidewall, across the tread, to the furthest point on the
opposite sidewall.
This number represents the width of a tire measured in inches when inflated. Width is measured in a straight
line from the furthest point on one sidewall, across the tread, to the furthest point on the opposite sidewall.
180/55-17
25x8x12
The aspect ratio indicates the height of the tire's cross-sectional profile. It is expressed as a percentage
of the tire's width, so an aspect ratio of 55 means the tire's cross-section is 55% as high as it is wide.
This number indicates the overall height of a tire measured in inches when the tire is inflated.
180/55-17
25x8x12
This number is the diameter of the rim on which the tire will fit. The number is expressed in inches.
This number represents the diameter of the tire's rim. The number is expressed in inches.