Measuring a PCD

What is a wheel PCD?

On any trailer wheel assembly or rim, the Pitch Circle Diameter (PCD) is the diameter of the circle which passes through the centre of all the wheel bolts or wheel rim holes.  The center of every bolt hole lies along the edge of the pitch circle and are evenly spaced. The pitch circle diameter is typically expressed in mm and is given along with the number of bolts/bolt holes. One example is 5x100; this means there are 5 bolts evenly spaced about a 100mm bolt circle.


an example of a 5x100 bolt pattern. The wheel has 5 lug nuts and utilizes a 100mm pitch circle diameter.


Measuring a PCD

The easiest fitment to measure is one with 4 lug nuts, you can measure from the center of one stud to the center of the stud directly opposite. However, for 5 stud and 6 stud PCD's you can use a simple method:

Measure the distance between two adjacent studs from the centre of each hole. and then use these simple formulae:


5 Stud PCD = S / 0.5878

6 Stud PCD = S / 0.5


Visit our trailer wheels and rims here and if you need any more help regarding measuring your PCD then contact our helpful team.