The tire size on the sidewall of a tire provides information about the tire's intended purpose, dimensions, load capacity and high temperature/high speed durability.
The linear distance in millimeters between the widest point of its outer sidewall to the widest point of its inner sidewall when mounted and measured on a specified width wheel.
Sidewall Aspect Ratio
This is also known as the Section Height which identifies the tire's profile. This is figured as a percentage of the section width. A tire size of 225/50R16 would have a section width of 225 millimeters and a section height of 50 percent of 225 millimeters.
The height of the wheel (rim) or the longest straight line that can be drawn between any two points on the rim measured in inches.