Lug Pattern vs Bolt Pattern
Lug pattern, bolt pattern, bolt circle and PCD all describe the same thing: the number of studs and the diameter of the circle through their centers.
Enter your numbers and press Calculate.
Same thing, four names
A pattern such as 5x114.3 gives the stud count and the diameter, in millimeters, of the circle through the stud centers. Written in inches it is 5x4.5. People call it the lug pattern, bolt pattern, bolt circle or PCD (pitch circle diameter).
| Metric | Inches | Neighbor studs (mm) |
|---|---|---|
| 4x100 | 4x3.94 | 70.7 |
| 4x108 | 4x4.25 | 76.4 |
| 4x114.3 | 4x4.50 | 80.8 |
| 5x100 | 5x3.94 | 58.8 |
| 5x108 | 5x4.25 | 63.5 |
| 5x112 | 5x4.41 | 65.8 |
| 5x114.3 | 5x4.50 | 67.2 |
| 5x120 | 5x4.72 | 70.5 |
| 5x127 | 5x5.00 | 74.6 |
| 5x135 | 5x5.31 | 79.4 |
| 5x139.7 | 5x5.50 | 82.1 |
| 6x114.3 | 6x4.50 | 57.1 |
| 6x135 | 6x5.31 | 67.5 |
| 6x139.7 | 6x5.50 | 69.8 |
| 8x165.1 | 8x6.50 | 63.2 |
| 8x170 | 8x6.69 | 65.1 |
Inches = mm ÷ 25.4. Neighboring-stud distance = bolt circle × sin(180° ÷ lugs).
What your tape should read
For 4, 6 and 8 lugs the first column is center to center straight across; for 5 lugs it is center to center across one skipped stud. The second column is the distance between neighboring studs, a handy cross-check on any pattern.
| Pattern | Main reading | Neighbor studs |
|---|---|---|
| 4x100 | 100.0 mm (3.94 in) | 70.7 mm (2.78 in) |
| 4x108 | 108.0 mm (4.25 in) | 76.4 mm (3.01 in) |
| 4x114.3 | 114.3 mm (4.50 in) | 80.8 mm (3.18 in) |
| 5x100 | 95.1 mm (3.74 in) | 58.8 mm (2.31 in) |
| 5x108 | 102.7 mm (4.04 in) | 63.5 mm (2.50 in) |
| 5x112 | 106.5 mm (4.19 in) | 65.8 mm (2.59 in) |
| 5x114.3 | 108.7 mm (4.28 in) | 67.2 mm (2.65 in) |
| 5x120 | 114.1 mm (4.49 in) | 70.5 mm (2.78 in) |
| 5x127 | 120.8 mm (4.76 in) | 74.6 mm (2.94 in) |
| 5x135 | 128.4 mm (5.05 in) | 79.4 mm (3.12 in) |
| 5x139.7 | 132.9 mm (5.23 in) | 82.1 mm (3.23 in) |
| 6x114.3 | 114.3 mm (4.50 in) | 57.1 mm (2.25 in) |
| 6x135 | 135.0 mm (5.31 in) | 67.5 mm (2.66 in) |
| 6x139.7 | 139.7 mm (5.50 in) | 69.8 mm (2.75 in) |
| 8x165.1 | 165.1 mm (6.50 in) | 63.2 mm (2.49 in) |
| 8x170 | 170.0 mm (6.69 in) | 65.1 mm (2.56 in) |
Computed from the bolt circle: straight across = PCD; skip one (5 lug) = PCD × sin 72°; neighbors = PCD × sin(180° ÷ lugs).
Before you buy wheels
- The stud count and bolt circle must match exactly; a wheel drilled a millimeter or two off will not seat properly on every stud.
- Check the center bore and the lug nut or bolt seat type along with the pattern.
- Use the size stamped on your current wheel rather than a tape reading when you can.
Sources
- https://tiregrades.com/tire-anatomy/wheels/how-to-measure-bolt-pattern
- https://www.cokertire.com/blog/measuring-wheel-bolt-pattern/
- https://store.gaugemagazine.com/blog/how-to-measure-a-bolt-pattern/
- https://drivenproducts.com/blogs/wheel-and-wheel-accessory-terminology/wheel-bolt-patterns-and-bolt-circles