Originally Posted by darren.cudd

get a piece of paper and do a rubbing off the back off the wheel so you get the outline of the stud holes. then take that piece of paper and a set of dividers and from the center of each of the holes draw an ark to the aprox center point of were the wheel center should be. after a few arcs you should be able to see the center point of the wheel in which case stick one end of the dividers in that center point then put the other end to the center of one of the whe nut holes. stick the diveders against a ruler to get the radius then just x 2 to get the diameter of the circle or pcd.