Tire sizes are simple to understand once you know how to read them. On this page you will find a detailed explanation of the 245/40R18 93W tire code.

245

This number indicates the tire has a width of 245 millimeters.

40

This number means that your tire has an aspect ratio of 40%. In other words, your tire's sidewall height (from the edge of the rim to the tire's tread) is 40% of the width. In this case, the sidewall height is 0 millimeters.

R

This letter indicates how your tire was constructed. Radial is the standard construction method for 99% of all tires sold today.

18

The tire size was designed to fit rims or wheels that are 18 inches in diameter.