How to Measure a Bolt Pattern
4, 6 and 8 lugs: center to center straight across. 5 lugs: center of one stud to the back of the farthest stud.
Enter your numbers and press Calculate.
Even number of lugs
Tiregrades: for 4-, 6- and 8-lug patterns, measure from the center of one stud to the center of the stud directly across. That is the bolt circle.
Five lugs
No stud sits directly across, so Tiregrades and Coker Tire both measure from the center of one stud to the back (far edge) of the farthest stud. Gauge Magazine gives a second method: center to center across one skipped stud, times 1.05. Driven Products cautions that a 5-lug tape measurement is only an estimate unless you use a bolt pattern gauge.
| 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