A wheel's bolt-circle-diameter is the diameter of an imaginary circle drawn through the center of the wheel's mounting-bolt holes. Different vehicle makes and models have varying bolt patterns.

If the pattern has an even number of mounting holes (four, six or eight lugs) simply measure from the center of one stud hole directly across the center of the wheel to the center of an opposite stud hole.

With a five-lug pattern, measure from the center of one stud hole to the center of the farthest stud hole, skipping the adjacent hole. The resulting measurement is slightly smaller than the actual bolt-circle diameter.

For example, a vehicle with a bolt pattern of (5 x 120) means this vehicle's hub has five bolts or lugs, which measure 120 millimeters apart from one another diagonally. Below is a chart on how to measure bolt patterns.

In the 5 bolt pattern the measure is not taking from the center on the hole or stud, but from one edge to the center on the 3er hole. not like on the 4 or 6 bolt pattern witch is measure from the center of the hole of stud to the oposite stud or hole.