How to measure a wheel PCD
How to Measure Wheel PCD (Pitch Circle Diameter)
PCD (Pitch Circle Diameter) is the diameter of the circle that passes through the centre of all wheel studs. It’s used to match the correct hub, disc, drum, or wheel to your trailer.
Important: Accurate measurements are critical. Measure centre-to-centre (not edge-to-edge), and use a vernier caliper if possible.
What you’ll need
- Vernier caliper (best) or a quality ruler/tape
- A clean hub face so you can clearly see stud centres
- Pen + paper (or use the quick formulas below)
Measure your stud pattern (4, 5 & 6 stud)
In the diagrams below, A = centre-to-centre distance to the nearest neighbouring stud. B = centre-to-centre distance to the furthest stud across the hub.
4 Stud
Source method: AL-KO “How to measure a PCD”.
5 Stud
Source method: AL-KO “How to measure a PCD”.
6 Stud
Source method: AL-KO “How to measure a PCD”.
Common stud patterns (quick reference)
Stud pattern is commonly written as “number of studs × PCD”. The table below lists common PCDs and stud threads referenced in the AL-KO chart.
| Common Name | Stud Pattern (as written) | PCD (mm) | Typical Stud Thread | Common Thread Options |
|---|---|---|---|---|
| Ford | 5 × 4.5" | 114.3 | 1/2" UNF | |
| Commodore | 5 × 120mm | 120 | 7/16" UNF | 12mm |
| HT | 5 × 4.25" | 108.0 | 7/16" UNF | |
| HQ | 5 × 4.75" | 120.65 | 7/16" UNF | |
| Gemini | 4 × 100mm | 100 | 7/16" UNF | |
| Honda | 4 × 100mm | 100 | 7/16" UNF | |
| Datsun | 4 × 4.5" | 114.3 | 7/16" UNF | |
| 5 stud LCR | 5 × 150mm | 150 | 9/16" UNF | 14mm |
| 6 stud LCR | 6 × 139.7mm | 139.7 | 1/2" UNF | 12mm |
| Nissan | 6 × 139.7mm | 139.7 | 1/2" UNF | 12mm |
| Range Rover | 5 × 6.5" | 165.1 | 5/8" UNF | |
| Ford F100 | 5 × 139.7mm | 139.7 | 1/2" UNF | 12mm |
| Bedford | 6 × 205mm | 205 | 7/8" UNF | |
| Land Rover Defender | 5 × 6.5" | 165.1 | 5/8" UNF | |
| Land Rover | 5 × 6.5" | 165.1 | 5/8" UNF | 9/16" UNF |
| New Navara, Nissan | 6 × 114.3 | 114.3 | 1/2" UNF |
Tips to get the right result
- Always measure from centre of stud to centre of stud.
- If you’re using a ruler, measure stud centre by measuring edge-to-edge and subtracting one stud diameter.
- Repeat the measurement twice and average it.
- Write your result as: (stud count) × (PCD) e.g. 6 × 139.7.
Measurement method and reference table adapted from AL-KO “How to measure a PCD” guide.