Measuring your Bolt Pattern
Measuring the 4, 6 and 8-bolt patterns: They are measured from the center of one lug hole to the center of the opposite hole.
Bolt measurement examples
Measuring a 5-bolt pattern: A 5-bolt pattern is very difficult to measure without using a bolt pattern gauge. Basically, you would measure the diameter of a circle that crosses through the center of the lug holes. This method is not recommended to confirm wheel fitment.
Bolt measurement
example