How to Measure a Bolt Pattern
A bolt pattern is two numbers: the lug count and the bolt circle — the diameter of the circle the stud centers sit on, in millimetres. 5x114.3 means five studs on a 114.3 mm circle. Even lug counts take one measurement. Five-lug hubs have no stud opposite any other, so you measure differently and convert.
What you need
- A tape measure (good to about ±1 mm) or a caliper (better).
- For the 5-lug skip-one method only: the stud diameter. Most modern cars and light trucks use 12 mm or 14 mm studs; it is printed on the vehicle's spec page here as thread pitch (M12x1.5, M14x1.5).
Step 1 — count the lugs
Count the studs on the hub, or the holes on the wheel. Cars and crossovers are mostly 4 or 5; half-ton trucks and SUVs are mostly 6; heavy-duty trucks are 8.
Step 2 — even lug counts (4, 6, 8): measure straight across
Measure center to center of two studs directly opposite each other. That distance is the bolt circle. No math. A 6-lug truck hub that measures 139.7 mm across is 6x139.7 (6x5.5").
Measuring the wheel instead of the hub works the same way: center of one hole to center of the opposite hole. Eyeballing the center of a hole is the hard part — a caliper on the hole edges, then adding one hole diameter, is more repeatable.
Step 3 — five lugs: two methods
With five studs there is nothing directly across from anything, so a straight-across measurement lands between two studs and means nothing. Use one of these.
Method A — adjacent studs (recommended)
Measure center to center of two neighbouring studs, then multiply by 1.7013. The number comes from geometry, not a rule of thumb: the five studs sit 72° apart, and the chord between neighbours is PCD × sin(36°).
Worked example: adjacent studs measure 67.2 mm → 67.2 × 1.7013 = 114.3 mm → 5x114.3.
Method B — skip-one (the shop method)
Measure from the far outer edge of one stud to the center of the stud two positions away. The old shop rule says that distance is the bolt circle. It is close, but off by half a stud diameter — roughly a millimetre — which is exactly the gap between 5x114.3 and 5x115. The exact version: subtract half the stud diameter, then divide by 0.9511 (sin 72°).
Worked example with 14 mm studs: edge-to-center measures 115.71 mm → (115.71 − 7) ÷ 0.9511 = 114.3 mm → 5x114.3. The uncorrected shop rule would have said 115.7 and pointed you at 5x115 — the wrong pattern.
The multiplier table
Adjacent-stud distance × multiplier = bolt circle, for any lug count. The multiplier is 1 ÷ sin(180° ÷ lugs).
| Lugs | Adjacent-stud multiplier | Or measure opposite studs? |
|---|---|---|
| 4 | × 1.4142 | Yes — straight across is the PCD |
| 5 | × 1.7013 | No opposite stud — use the multiplier |
| 6 | × 2.0000 | Yes — straight across is the PCD |
| 8 | × 2.6131 | Yes — straight across is the PCD |
Example on a 6-lug hub: adjacent studs 69.85 mm × 2 = 139.7 mm, the same answer as measuring straight across.
Step 4 — match to a standard pattern, and the trap
Your measurement will not land exactly on a standard number; round to the nearest one and convert to inches by dividing by 25.4 if you need it (114.3 mm = 4.5"). The full list of patterns we track is on the bolt pattern chart.
The trap: some standard patterns are closer together than a tape measure can resolve, and they are not interchangeable. A wheel drilled for one will bolt onto the other, sit a fraction of a millimetre off-center, and load the studs unevenly.
| Lugs | Pattern A | Pattern B | Gap |
|---|---|---|---|
| 5 | 5x114.3 | 5x115 | 0.70 mm |
| 5 | 5x120 | 5x120.65 | 0.65 mm |
If your number falls between one of these pairs, do not pick by eye. Look the vehicle up — the finder and every vehicle page state the pattern from manufacturer documents, with the source cited.
Pattern matches — what else has to
A matching bolt pattern is necessary, not sufficient. The wheel's center bore must be at least the hub's diameter, the lug nuts or bolts must match the stud thread and the wheel's seat type, and on European cars that use wheel bolts instead of studs, bolt length matters too. Each vehicle page lists all of these.
Tools that use this
Bolt pattern measurement calculator →
Bolt pattern converter (mm ↔ inch) →
Bolt pattern finder by vehicle →
Frequently asked
How do you measure a 5 lug bolt pattern?
Measure center-to-center of two adjacent studs and multiply by 1.7013 — or measure from the outer edge of one stud to the center of the stud two positions over, subtract half the stud diameter, and divide by 0.9511. There is no stud directly opposite on a 5-lug hub, so a straight-across measurement means nothing.
How do you measure an 8 lug bolt pattern?
Center-to-center of two directly opposite studs. On any even lug count (4, 6, 8) that distance is the bolt circle itself — no multiplier. 165.1 mm across is 8x165.1 (8x6.5"); 170 mm is 8x170; 180 mm is 8x180.
Is 5x4.5 and 5x114.3 the same bolt pattern?
Yes. 5x4.5 is the inch notation and 5x114.3 the metric notation of the same pattern: 4.5 in × 25.4 = 114.3 mm.
How do I properly measure a bolt pattern?
Measure stud centers, not edges (a caliper on the hole edges plus one hole diameter is more repeatable than eyeballing centers). Use the right method for the lug count, convert, and then match to a standard pattern — and if your number falls between two standards less than about a millimetre apart, such as 5x114.3 and 5x115, confirm by vehicle lookup instead of picking by eye.