Choosing the right trailer wheel starts with knowing your bolt pattern. This measurement identifies how many wheel studs or bolt holes your trailer hub has and the diameter of the circle they form—also called the pitch circle diameter (PCD).
You only need to measure your trailer’s bolt pattern when selecting a replacement wheel or a complete wheel-and-tire assembly. If you are replacing only the tire and keeping your existing wheel, the bolt pattern does not affect tire fitment. However, you will still need to confirm the tire size, load capacity, and other tire specifications.
When bolt pattern matters
| What you’re buying | Do you need the bolt pattern? | Why |
| Trailer tire only | Usually no | You need the existing tire size, load range, speed rating, and application requirements—not the wheel’s mounting pattern. |
| Trailer wheel only | Yes | The wheel’s number of lugs and bolt-circle diameter must match the trailer hub exactly. |
| Wheel-and-tire assembly | Yes | The tire may fit the wheel, but the wheel still needs to mount correctly to the trailer hub. |
| Spare tire on an existing wheel | Usually no | If you are reusing your current spare wheel, match the replacement tire to that wheel’s size and specifications. |
| Complete spare wheel-and-tire assembly | Yes | The spare wheel must match the trailer’s hub bolt pattern to be usable in an emergency. |
