To calculate the P.C.D. of a three stud wheel or hub measure between two holes next to each other (as with five stud below) and multiply by 1.154.
Four or Six Stud
The P.C.D. of any wheel or hub with an even number of holes can be measured from the inside of one hole directly across to the outside of the hole opposite.
To calculate the P.C.D. of a five stud wheel or hub, measure 'X' from the inside of one hole to the outside of the next hole and multiply by 1.7012. The table below is a reference guide for some common sizes.