Measuring your bolt/lug pattern can be simple and can also be a little tricky. Many of the Lug Patterns used today are 5 lugs, these can be tricky because your actualy trying to measure the diameter of an imaginary circle. Most people in the tire/wheel industry would tell you to just measure from the center of one bolt to the back side of the bolt across from it. Another method would be to measure from the center of one bolt to the center of the bolt across from it and multiply by 1.05. You could also use a tool like the Bolt Pattern Pro this will give you the most accurate measurement.
Measuring 4 Lug Patterns are easy, just measure from the center of one bolt to the center of the bolt across from it.
Measure from the center of one bolt to the center of the bolt across from it and multiply by 1.05 or measure from the center of one bolt to the back side of the bolt across from it. These methods will get you very close to your bolt pattern.
Measuring 6 Lug Patterns are as easy as 4 Lug, just measure from the center of one bolt to the center of the bolt across from it.
Measure from the center of one bolt to the center of the bolt across from it and multiply by 1.026 or measure from the center of one bolt to the back side of the bolt across from it. These methods will get you very close to your bolt pattern.