What does PCD mean?
The Pitch Circle Diameter (PCD) is the diameter of the circle which passes through the centre of all the studs, wheel bolts or wheel rim holes.
The easiest way calculate the PCD is as follows:
1) Measure the distance ‘S’ between two adjacent studs from the centre of each hole.
2) Calculate from the formula below
**Note: on 4 lug fitments you can measure from the center of one stud to the center of the stud directly opposite.
PCD Calculation Formula
4 Stud PCD = S / 0.7071
5 Stud PCD = S / 0.5278
6 Stud PCD = S / 0.5
–Courtesy of YHI