The numbers on the side of a tire will tell you information about the size of the tire. We will use the following tire rating for an example: 185/60R14. The first number tells you the width of the tire in millimeters so in our example this tire would be 185mm. The second number tells you the aspect ratio or the ratio of height to width of the tire which would be 60 in our example. The final number tells you the diameter of the tire in inches which would be 14′ in our example above.