Hub Bore Comparator
Check that the center hole fits your hub. Use the calculator below. Results update as you type.
How the Hub Bore Comparator Works
This comparator works by comparing the wheel's center bore with the vehicle's hub diameter. The wheel bore must be equal to or larger than the hub.
- Enter the vehicle's hub bore, for example 64.1 mm.
- Enter the wheel's center bore, for example 73.1 mm.
- Read the gap: 9.0 mm in diameter, 4.50 mm per side.
- Read the fix: a 73.1 → 64.1 hub-centric ring.
The Formula
The formula is Gap per Side = (Wheel Bore − Hub Bore) ÷ 2.
Gap per Side (mm) = (Bore_wheel − Bore_hub) ÷ 2 Fit = Bore_wheel ≥ Bore_hub Ring Size = Bore_wheel → Bore_hubWorked example: a 73.1 mm wheel on a 57.1 mm hub has an 8.00 mm gap per side. A 73.1 → 57.1 ring closes it.
Conversion Table
The conversion table lists 15 common hub bores, their inch values and the ring needed in a 73.1 mm aftermarket wheel. Hubs larger than 73.1 mm cannot use that wheel.
73.1 mm is a common bore size for aftermarket wheels. The same method works for any wheel bore.
| Hub Bore (mm) | Hub Bore (in) | Ring for 73.1 mm Wheel | Gap Without Ring (mm per side) |
|---|---|---|---|
| 54.1 | 2.130 | 73.1 → 54.1 | 9.50 |
| 56.1 | 2.209 | 73.1 → 56.1 | 8.50 |
| 57.1 | 2.248 | 73.1 → 57.1 | 8.00 |
| 60.1 | 2.366 | 73.1 → 60.1 | 6.50 |
| 63.4 | 2.496 | 73.1 → 63.4 | 4.85 |
| 64.1 | 2.524 | 73.1 → 64.1 | 4.50 |
| 66.1 | 2.602 | 73.1 → 66.1 | 3.50 |
| 66.6 | 2.622 | 73.1 → 66.6 | 3.25 |
| 67.1 | 2.642 | 73.1 → 67.1 | 3.00 |
| 70.5 | 2.776 | 73.1 → 70.5 | 1.30 |
| 71.5 | 2.815 | 73.1 → 71.5 | 0.80 |
| 72.6 | 2.858 | 73.1 → 72.6 | 0.25 |
| 78.1 | 3.075 | Wheel too small | — |
| 87.1 | 3.429 | Wheel too small | — |
| 106.1 | 4.177 | Wheel too small | — |
What Is the Hub Bore Comparator?
The Hub Bore Comparator is a tool that checks center bore fit between a wheel and a vehicle hub. A hub-centric fit centers the wheel on the hub; a lug-centric fit relies on the lug nuts.
Aftermarket wheels use a large bore to fit many vehicles. A hub-centric ring fills the gap, which cuts vibration and stops the lug studs from carrying the wheel's weight.
Common Uses
This comparator has 4 uses: ring sizing, vibration diagnosis, wheel shopping and spare checks.
- Size rings: Order the right hub-centric ring.
- Diagnose vibration: Spot missing rings on aftermarket wheels.
- Shop for wheels: Confirm the bore is large enough.
- Check spares: Confirm a spare fits the hub.