The wheel bolt pattern is merely the number of bolts on the wheel. The important measurement is the "pitch circle diameter".
The bolt pattern is merely the number of bolts on the wheel. As the bolts will be evenly spaced, the number determines the bolt pattern. The bolt circle is the circle determined by the positions of the bolts; the center of every bolt lies on the circumference of the bolt circle. The important measurement is the "pitch circle diameter" (PCD).
For a 4- or 6-bolt car, this measurement is merely the distance between the center of two diametrically opposite bolts.
If your wheel has a 5-bolt pattern, measure from the BACK of one bolt hole to the center of the second bolt hole as shown in the diagram. RACING GO KART 3-LUG BOLT PATTERN
3-Lug: Diameter of a virtual circle passing through the center of all three bolt holes.
Example: American bolt hole pattern, measurement "a" is 2-1/2''.