Identify and convert a bolt pattern
A bolt pattern is a lug count and the diameter of the circle their centres sit on. Enter the pattern if you know it, or measure between two adjacent studs and let the tool work backwards.
Also written 5x4.5 in imperial catalogues. Commonly found on: Ford Mustang, Explorer, Camry, Accord, Jeep Cherokee. Matching the pattern is necessary but not sufficient — the wheel still has to clear the brakes, match the centre bore and carry a workable offset. Be careful of 5x115 and 5x112: close enough to thread on, far enough to seat the wheel off-centre.
| Pattern | Imperial | Difference | Compatible? | Commonly found on |
|---|---|---|---|---|
| 5x114.3 | 5x4.5 | — | Yes — same circle | Ford Mustang, Explorer, Camry, Accord, Jeep Cherokee |
| 5x115 | 5x4.53 | +0.7 mm | No — do not force | Chevrolet Impala, Malibu (older), Buick |
| 5x112 | 5x4.41 | −2.3 mm | No — do not force | Audi, Mercedes-Benz, VW MQB platform |
| 5x110 | 5x4.33 | −4.3 mm | No — do not force | Chevrolet Malibu, Equinox, Saab, Alfa Romeo |
| 5x120 | 5x4.72 | +5.7 mm | No — do not force | BMW (most), Chevrolet Colorado, Acura MDX |
| Metric | Imperial | Where you see it |
|---|---|---|
| 4x100 | 4x3.94 | Common on small front-wheel-drive cars |
| 5x114.3 | 5x4.5 | The most widespread five-lug pattern in North America |
| 5x120.7 | 5x4.75 | Long-standing GM pattern |
| 5x127 | 5x5 | Jeep and older GM |
| 5x139.7 | 5x5.5 | Light trucks and older four-wheel drives |
| 6x139.7 | 6x5.5 | Mid-size and older full-size trucks |
| 8x165.1 | 8x6.5 | Heavy-duty trucks |
Pattern confirmed? Check the offset next — a wheel with the right pattern still has to sit in the right place. Tightening torque for your vehicle is on its lug nut specification page.
Getting a number you can act on
- 01Count the studs first
Lug count is never interchangeable. A five-lug wheel does not go on a six-lug hub under any circumstances, and no adapter makes that a good idea on a road vehicle.
- 02Use the known pattern if you have it
Most wheels have it stamped on the back, and most vehicle documentation lists it. Enter it directly and the tool gives you both unit forms plus the compatibility picture.
- 03Otherwise measure between adjacent studs
Centre to centre on two neighbouring studs, in millimetres. The tool works the pitch circle backwards from that, which avoids the awkward across-the-hub measurement entirely.
- 04Read the compatibility table carefully
Only the row marked as the same circle is interchangeable. Everything else in the list is there as a warning, not a suggestion — those are the patterns close enough to mislead you.
- 05Check the rest of the fitment
Pattern is necessary and nowhere near sufficient. Centre bore, offset, brake clearance and load rating all have to work too, and any one of them can rule a wheel out.
What the calculator is actually doing
Nothing here is proprietary. If you would rather check it by hand, or explain it to someone at a counter, these are the same expressions the tool evaluates.
chord = PCD × sin(180° ÷ number of lugs)The straight-line distance between two neighbouring stud centres. On a 5x114.3 that is 67.18 mm.
PCD = chord ÷ sin(180° ÷ number of lugs)The same relationship reversed, and the reason you never have to measure across an odd-lug hub.
PCD (in) = PCD (mm) ÷ 25.4114.3 mm is exactly 4.5 inches, which is why 5x114.3 and 5x4.5 are the same pattern.
|difference| ≤ 0.5 mm → same circleInside half a millimetre the studs line up within normal tolerance. Outside it, they do not, however easily the wheel threads on.
Why five-lug patterns are the awkward ones
On an even-lug hub the pitch circle diameter is easy to measure: studs sit directly opposite each other, so you measure straight across from one centre to the opposite centre and you have it.
Five lugs have no opposite stud. Nothing sits across from anything, which is why the traditional method is a fiddly measurement from the centre of one stud to the far edge of the stud two positions away — and why people get it wrong.
The reliable approach is to measure between two adjacent studs instead, centre to centre, and calculate the pitch circle from that. The relationship is fixed: the chord between neighbours is the pitch circle multiplied by the sine of 180 degrees divided by the lug count. For five lugs that factor is 0.5878, so a 67.18 mm gap means a 114.3 mm circle.
This matters because the patterns that get confused are only a millimetre or two apart. A measurement that is 2 mm out is enough to identify the wrong pattern entirely, and the wrong pattern is exactly the failure this tool exists to prevent.
The patterns that are close enough to be dangerous
This is the part most bolt pattern tools leave out, and it is the part that damages wheels.
Around the 5-lug 110 to 120 mm range there are at least five distinct patterns: 110, 112, 114.3, 115 and 120. The gap between 5x114.3 and 5x115 is seven tenths of a millimetre. A wheel with one pattern will start onto studs of the other, and the lug nuts will turn, and it will feel as though it fits.
It does not. The wheel is being pulled off centre by a fraction of a millimetre at each stud, which loads every stud in bending rather than tension. The consequences arrive later, as elongated stud holes, loosening lug nuts, vibration, and eventually sheared studs at speed.
The rule is simple and worth holding to: within about half a millimetre the patterns are the same circle expressed two ways, and interchangeable. Beyond that they are different patterns, and the fact that a nut will thread on tells you nothing at all.
What else has to line up
- Centre bore — the hole must clear the hub, and rings only correct an oversized bore, never an undersized one
- Offset and backspacing — the right pattern in the wrong position still rubs
- Brake clearance — caliper shape rules out many wheels that bolt on perfectly
- Stud or bolt thread size and seat type, which must match the lug nuts you are using
- Load rating, which matters most on trucks and anything that tows
- Tightening torque, which is a vehicle specification rather than a wheel one
Why the two unit systems both persist
The split is historical rather than technical, and it survives because both notations describe real hardware that is still in service.
Imperial patterns came first in North America, which is why so many round numbers appear in inches: 5x4.5, 5x4.75, 5x5, 5x5.5, 6x5.5, 8x6.5. Converted to millimetres those become the awkward-looking 114.3, 120.65, 127, 139.7, 139.7 and 165.1 — numbers that look arbitrary until you divide them by 25.4.
Metric patterns from European and Japanese manufacturers do the reverse: 100, 108, 112, 120 and 130 are clean in millimetres and untidy in inches.
The practical consequence is that a pattern which looks unfamiliar may simply be one you know, written the other way. Before concluding that a wheel does not fit, convert — a great many apparent mismatches are the same circle under a different name.
Bolt Pattern Calculator FAQ
How do I measure a 5-lug bolt pattern?+
Measure centre to centre between two adjacent studs, then divide by 0.5878 to get the pitch circle diameter. On a 5x114.3 the adjacent spacing is 67.18 mm. Five-lug hubs have no opposite stud, so this is more reliable than measuring across.
Is 5x114.3 the same as 5x4.5?+
Yes, exactly. 114.3 mm divided by 25.4 is precisely 4.5 inches — the same circle written in two unit systems.
Will a 5x115 wheel fit a 5x114.3 hub?+
No. The patterns are 0.7 mm apart, which is enough to thread the nuts on while holding the wheel off centre. That loads the studs in bending and leads to elongated holes, loosening nuts and eventually sheared studs.
How close do two bolt patterns have to be to interchange?+
Within about half a millimetre. Inside that the studs line up within normal manufacturing tolerance. Beyond it they do not, regardless of whether the wheel appears to bolt up.
What does PCD mean?+
Pitch circle diameter — the diameter of the imaginary circle passing through the centre of every stud or bolt hole. It is the second number in a designation like 5x114.3.
Can I use adapters to change bolt pattern?+
They exist, and they move the wheel outboard by their own thickness while adding a bolted joint into the load path. On a road vehicle that is a decision to make deliberately, with correctly rated hardware and adequate remaining stud engagement.
Does bolt pattern determine whether a wheel fits?+
Only partly. Centre bore, offset, brake clearance, thread size, seat type and load rating all have to work as well. Pattern is the first check, not the last.
Why are truck patterns quoted in inches so often?+
Because they were designed in inches. 6x5.5 and 8x6.5 are clean imperial figures that become 139.7 mm and 165.1 mm when converted, which is why those metric numbers look so arbitrary.
Standards and references behind these figures
The arithmetic on this page is fixed, but the boundaries and conventions around it come from published standards and manufacturer guidance. These are the documents they come from, so you can check them rather than take them on trust.
01The Tire and Rim Association — standards filing (NHTSA docket)TRA has been the US standardising body for tire and rim interchangeability since 1903; this filing sets out dimensional practice.↗02ISO 5775 — tire and rim designationsThe international designation system that sits alongside TRA and ETRTO practice.↗03TireGrades — minimum and maximum tire size for a given rim widthSummarises the approved rim-width range published for each section width by TRA and ETRTO.↗The wheel is only half the fitment. This calculates where the rim sits. The tire mounted on it reaches further out and further in than the rim does, and that rubber is what makes contact. Check the actual gaps at the strut and inside the fender, at full steering lock and full suspension compression, before ordering.