How To Calculate PCD

What is pitch circle diameter (PCD)?

Pitch Circle Diameter (PCD) is the diameter of the circle that the wheel studs form.

How to calculate the PCD

Measure the distance between two adjacent studs (measure from the centre of the studs). Once you have this measurement, use the formulas below to calculate the PCD. The measurement between the two studs is indicated as ‘S’ in these formulas.


3 Stud PCD = ‘S’ / 1.155
4 Stud PCD = ‘S’ / 0.7071
5 Stud PCD = ‘S’ / 0.5878
6 Stud PCD = ‘S’ / 0.5
8 Stud PCD = ‘S’ / 2.613