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.

Image

PCD Calculator

mm

Popular wheel Sizes

Rim Size Studs    S   PCD
8" 3 76.90mm 88.8mm
8" 3 95.26mm 110mm
8" 4 70.71mm 100mm
8" 4 71.84mm 101.6mm (4")
8" 4 81.32mm 115mm
8" 4 91.92mm 130mm
10" 4 70.71mm 100mm
10" 4 71.84mm 101.6mm (4")
10" 4 79.20mm 112mm
10" 5 65.83mm 112mm
10" 4 81.32mm 115mm
10" 4 91.92mm 130mm
10" 4 98.78mm 139.7mm (5")
12" 4 70.71mm 100mm
12" 4 71.84mm 101.6mm (4")
12" 5 65.83mm 112mm
12" 4 91.92mm 130mm
12" 4 98.78mm 139.7mm (5½")
12" 5 82.29mm 140mm
12" 5 97.04mm 165.1mm (6½")
13" 4 70.71mm 100mm
13" 4 79.20mm 112mm
13" 5 65.83mm 112mm
13" 4 91.92mm 130mm
13" 4 98.78mm 139.7mm (5½")
13" 5 82.29mm 140mm
13" 5 97.04mm 165.1mm (6½")
14" 4 70.71mm 100mm
14" 5 65.83mm 112mm
14" 5 82.29mm 140mm
14" 5 89.58mm 152.4mm (6")
14" 6 102.5mm 205mm
16" 5 97.04mm 165.1mm (6")

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.



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