Tooling and hardware
Wheel bolt pattern chart
Measure center to center between two neighboring studs and divide by sin(180 / n); a 5-lug pattern reading 2.645 in is 5 x 114.3 mm (5 x 4.5 in).
Technical review pending. Formulas and values are cited. This notice comes down after a machinist review.
| Pattern | BCD (mm) | BCD (in) | Adjacent stud distance (mm) | Adjacent stud distance (in) |
|---|---|---|---|---|
| 4x100 | 100 | 3.937 | 70.71 | 2.784 |
| 4x108 | 108 | 4.252 | 76.37 | 3.007 |
| 4x114.3 | 114.3 | 4.500 | 80.82 | 3.182 |
| 5x100 | 100 | 3.937 | 58.78 | 2.314 |
| 5x108 | 108 | 4.252 | 63.48 | 2.499 |
| 5x112 | 112 | 4.409 | 65.83 | 2.592 |
| 5x114.3 | 114.3 | 4.500 | 67.18 | 2.645 |
| 5x120 | 120 | 4.724 | 70.53 | 2.777 |
| 5x127 | 127 | 5.000 | 74.65 | 2.939 |
| 5x130 | 130 | 5.118 | 76.41 | 3.008 |
| 5x139.7 | 139.7 | 5.500 | 82.11 | 3.233 |
| 6x114.3 | 114.3 | 4.500 | 57.15 | 2.250 |
| 6x135 | 135 | 5.315 | 67.50 | 2.657 |
| 6x139.7 | 139.7 | 5.500 | 69.85 | 2.750 |
| 8x165.1 | 165.1 | 6.500 | 63.18 | 2.487 |
| 8x170 | 170 | 6.693 | 65.06 | 2.561 |
Computed from a = BCD x sin(180° / n) with unrounded values, then rounded once: mm to 2 places, inch to 3. Adjacent stud distance is center to center between neighboring studs.
Source: Bolt circle geometry (Machinery's Handbook, equally spaced holes). Pattern sizes are common vehicle-maker designations.
Wheel fitment is a safety item; confirm every spec with the vehicle maker before mounting.
How to read the table
The pattern is stud count x bolt circle diameter (BCD, also called PCD) in mm. Find your stud count, then match the center-to-center distance you measured between two neighboring studs. On 4, 6 and 8 lug patterns you can also measure across opposite studs: that reading is the BCD.
Bolt circle from neighboring stud distance
Bolt circle diameter (BCD)
in
BCD = a / sin(180° / n) = 2.645 / sin(180° / 5) = 4.500 in
114.30 mm. Nearest in this table: 5x114.3, 0.00 mm away. Confirm with the vehicle maker's spec.
How it works
BCD = a / sin(180° / n); a = BCD x sin(180° / n)
| Symbol | Meaning | Unit |
|---|---|---|
| BCD | Bolt circle diameter, also called PCD | mm or in |
| n | Number of studs | studs |
| a | Adjacent stud distance, center to center | mm or in |
| sin(180° / n) | 4 lug 0.70711, 5 lug 0.58779, 6 lug 0.50000, 8 lug 0.38268 | none |
Multiplying works too: BCD = a x 1.41421 (4 lug), a x 1.70130 (5 lug), a x 2 (6 lug) or a x 2.61313 (8 lug). The math is the same chord formula used for any equally spaced bolt circle.
Worked example: 5 lug, 2.645 in between studs
Five studs, 2.645 in center to center between two neighbors.
- sin(180° / 5) = sin 36° = 0.58779.
- BCD = 2.645 / 0.58779 = 4.500 in.
- In mm: 4.500 x 25.4 = 114.30 mm.
Result: 4.500 in (114.30 mm), a 5x114.3 (5 x 4.5 in) pattern.
Worked example: 6 lug, 69.85 mm between studs
Six studs, 69.85 mm center to center between two neighbors.
- sin(180° / 6) = sin 30° = 0.5.
- BCD = 69.85 / 0.5 = 139.70 mm.
- In inches: 139.70 / 25.4 = 5.500 in.
Result: 139.70 mm (5.500 in), a 6x139.7 (6 x 5.5 in) pattern.
Shop notes
- Close patterns differ by under 2 mm of stud distance, for example 5x114.3 against 5x115, or 5x112 against 5x114.3. Confirm with the vehicle maker's spec.
- Pattern alone does not make a wheel fit. Center bore, offset and stud thread also have to match.
- On 4, 6 and 8 lug patterns, the center-to-center reading across opposite studs is the BCD with no math.
FAQ
How do you measure a 5-lug bolt pattern?
Measure two neighboring studs center to center and divide by 0.58779 (sin 36°). 2.645 in gives 4.500 in (114.30 mm), a 5x114.3 pattern.
Is 5x4.5 the same as 5x114.3?
Yes. 4.500 in x 25.4 = 114.3 mm.
How do you measure a 6-lug pattern?
Measure across opposite studs center to center; on an even stud count that reading is the bolt circle. Or measure neighboring studs and multiply by 2, since sin 30° = 0.5.
What is 8x6.5 in metric?
165.1 mm (6.500 in x 25.4). Neighboring studs sit 63.18 mm (2.487 in) apart.
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