Frequently Asked Questions
The 215/65R15 tire is a well-known notation used in the tire industry. The first quantity, 215,
represents the width of the tire in millimeters. The second number, 65, is the aspect ratio,
eventually which is the height of the tire’s sidewall as a percent of its width.
However, the R stands for radial, indicating the tire’s production type. The tire is designed to
fit a wheel with a diameter of 15 inches, which is the last number.
The peak (or diameter) of a 215/65R15 tire is about 26 inches. And, to calculate this, multiply the width of the tire (215mm) by the aspect ratio (65%) twice (once for the top sidewall and once for the bottom), and then add the diameter of the wheel (15 inches).
The width of a 215/65R15 tire is 215 mm, which is about 8.5 inches. So, this is the linear distance among the rims of the tire’s tread, providing the touch patch with the street.
