Tires: Wheels/Rims, wheels rims, rim size

Question
How do you measure the size of a rim on a vehicle?

Answer
Babatunde,

The rim should be stamped with the nominal size somewhere.  The dimensions are typically in inches and the rim size will be expressed as 15 X 7.5 - with the 15 being the diameter (which must be exactly that same as the last number of the tire size) and the 7.5 being the width of the rim between the flanges and the width is usually in 1/2" increments.

There are other dimensions that might be important - offset for example.  Here's a graphic that will help:

http://www.rims-n-tires.com/rt_specs.jsp