# Tyre Rolling Circumference

The effective circumference of a tyre loaded against a surface.

Where

R = rim size [inches]

W = tyre width

P = tyre profile

Example: for a tyre size of 245 35 R17 this gives a rolling radius = 1854mm

Calculated Rolling Circumference using above formula versus quoted Rolling Circumference

The equation is for the best fit straight line through the data points, this

should be y=x to be a perfect fit.

**See also: **Tyre, Tyre Rolling Radius.

**Subjects: ** Automotive