Bolt patterns with an even number of lugs are measured from the center of 2 directly opposite bolts, while 5 lug bolt patterns are measured from the side of one and the center of one of the opposite bolts. To find your bolt pattern, measure the distance as accurately as possible and then find the corresponding bolt pattern in this conversion table. For example, if you have a 5 lug wheel and your measurement is 5" then your bolt pattern is 5 x 5" (5 x 127mm).