What does 175-70R13 mean?

Tire sizes are easy to understand once you learn how to read them.  On this page you'll find a color-coded explanation of the 175-70R13 tire code.

175

This number indicates that your tire has a width of 175 millimeters.

13

The tire size was designed to fit rims or wheels that are 13 inches in diameter.

70

This number means that your tire has an aspect ratio of 70%.  In other words, your tire's sidewall height (from the edge of the rim to the tire's tread) is 70% of the width.  In this case, the sidewall height works out to be 122 millimeters.

R

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

RRadial
BBias Belt
DDiagonal