How to calculate the PCD – Pitch circle diameter

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. Identify the size of rim or tyre size. (This helps to narrow down the likely PCD sizes)
  2. Measure the distance ‘S’ between two adjacent studs from the centre of each hole.
  3. Using the calculator enter the number of studs/holes & ‘S’ and press ‘calculate’.
  4. Using the relevant diagram depending on the number of studs you have you should be able to identify the correct PCD.

Note: Imperial sizes are commonly used on UK trailers whereas European trailers use metric. PCD Calculation 4, 5 & 6 hole

Pitch Circle Diameter – PCD Calculator

 

mm
 

Popular wheel Sizes & Stud Patterns

Rim Size Studs   S  PCD
8"376.90mm88.8mm
8"395.26mm110mm
8"470.71mm100mm
8"471.84mm101.6mm (4")
8"481.32mm115mm
8"491.92mm130mm
10"470.71mm100mm
10"471.84mm101.6mm (4")
10"479.20mm112mm
10"565.83mm112mm
10"481.32mm115mm
10"491.92mm130mm
10"498.78mm139.7mm (5½")
12"470.71mm100mm
12"471.84mm101.6mm (4")
12"565.83mm112mm
12"491.92mm130mm
12"498.78mm139.7mm (5½")
12"582.29mm140mm
12"597.04mm165.1mm (6½")
13"470.71mm100mm
13"479.20mm112mm
13"565.83mm112mm
13"491.92mm130mm
13"498.78mm139.7mm (5½")
13"582.29mm140mm
13"597.04mm165.1mm (6½")
14"470.71mm100mm
14"565.83mm112mm
14"582.29mm140mm
14"589.58mm152.4mm (6")
14"6102.5mm205mm
16"597.04mm165.1mm (6½")
 

Pitch Circle Diameter – PCD Calculation Formula

 
4 Stud PCD =S
0.7071
  
5 Stud PCD =S
0.5878
  
6 Stud PCD = S
0.5

How to find the Offset of a wheel rim

Please Click Here If you need to find the OFFSET of the wheel rim.