How to measure a wheel bolt pattern, including five studs

The first number is the number of wheel fasteners. The second is the diameter of the circle running through their centres, usually in millimetres. PCD stands for pitch circle diameter. A 5×114.3 pattern therefore has five equally spaced fasteners whose centres lie on a 114.3 mm circle. It does not mean the holes are 114.3 mm apart.

Some suppliers use inches. Exactly 4.5 inches is 114.3 mm, so 5×4.5 and 5×114.3 describe the same nominal pattern. Exactly 5.5 inches is 139.7 mm. Do the conversion using 25.4 mm per inch rather than treating a nearby whole millimetre value as equivalent. Similar-looking patterns can be genuinely different.

Check the vehicle information and wheel part number before measuring. A measurement is especially useful for an unknown used wheel, but it should support identification rather than override a reliable manufacturer specification. Previous owners may also have fitted adapters, so the visible wheel pattern is not always the original hub pattern.

For an even number of equally spaced studs, measure from the centre of one to the centre of the directly opposite stud. That distance is the PCD. On a bare wheel, use the centres of the mounting holes instead. Do not include an outer edge at one end and a centre at the other: that adds part of a hole or stud diameter.

A caliper can make centre measurement easier if the studs are the same diameter. Measuring from the same side of one stud to the same side of its opposite gives the centre distance. Measuring across the outside of both studs requires subtracting one stud diameter. Record which method you used so another person can check it.

• Clean enough dirt away to see the true stud or hole boundaries.
• Confirm which holes actually mount the wheel, especially on a wheel with multiple drilled patterns.
• Measure across more than one opposite pair.
• Use a proper PCD gauge if readings are too close to distinguish possible patterns.

Five studs have no opposite pair, so a straight line between two stud centres is a chord of the circle, not its diameter. Measuring from a centre to the far edge of a distant hole is a familiar shortcut, but its accuracy depends on the hole dimensions. It is not a reliable way to separate very similar patterns.

A PCD gauge or the wheel manufacturer's drawing is the simplest final check. If you want to understand the geometry, measure the centre distance between adjacent studs and divide by sin(36°), approximately 0.5878. Alternatively, measure between centres while skipping one stud and divide by sin(72°), approximately 0.9511. Both methods assume five equally spaced holes and accurate centre measurements.

For a theoretical 5×114.3 pattern, adjacent centres are about 67.18 mm apart. The distance when skipping one stud is about 108.71 mm. Neither is the PCD itself. Dividing 67.18 by 0.5878 gives approximately 114.3 mm, allowing for rounding. The maths is straightforward; finding the exact centres with a tape is the weak point.

Wheel fastener holes may have a countersunk seat, a straight bore and a larger opening at the surface. Those are different diameters. A tape stretched across the large opening does not automatically find the bolt centre. Corrosion, paint build-up and damaged seats can make the apparent edges uneven as well.

A wheel drilled for two patterns needs each set identified separately. Do not simply count ten holes and describe it as a ten stud wheel. Trace the five holes that form one equally spaced circle, then identify the other set. If the pattern cannot be established without guesswork, ask the manufacturer or leave that used set alone.

Do not use bolts to pull a nearly matching wheel into position. A wheel beginning to slide over the studs is not evidence that its mounting seats align. Special adaptation hardware, where approved for a particular application, requires its own engineering and instructions. Ordinary wheel fasteners are not a tool for correcting the wrong PCD.

After confirming PCD, compare centre bore, fastener thread, seat shape, width, offset, diameter and load rating. The wheel's brake clearance also depends on spoke and barrel shape. A used wheel from another car can pass the bolt-pattern test and fail several of these checks. Treat shared PCD as a search filter, not permission to swap.

For example, imagine two unnamed cars that both use 5×114.3. One wheel has a smaller centre bore than the second car's hub. It cannot seat properly just because the studs line up. A centring ring can reduce a larger compatible wheel bore to a smaller hub; it cannot enlarge a bore that is too small.

Write the findings on one sheet and keep photographs of the rear wheel markings. Ask the supplier to confirm the exact part number against your car, brakes and proposed tyre. If the wheel is unmarked, modified or sold without enough information to verify its load capacity, a cheap purchase can become a costly identification exercise.

• Search published cars by bolt pattern
• Understand hub bores and centring rings