A trailer wheel bolt pattern is written as two numbers: the number of lug holes and the diameter in inches of the circle they form. Example: 5x4.5 means five lugs on a 4.5-inch circle. To find yours, count the lugs, take one measurement as shown below, and match it in the chart.
Step 1: Count the lug holes
Look at your hub or the back of the wheel and count the holes. Trailer wheels almost always have 4, 5, 6, or 8 lugs. The replacement wheel must match this number exactly.
Step 2: Measure the circle
Even lug counts (4, 6, or 8 holes)
Measure from the center of one hole straight across to the center of the hole directly opposite. That distance is your bolt circle diameter. Done.
Odd lug counts (5 holes)
With five lugs there is no hole directly opposite, so measure the center-to-center distance of two adjacent holes and match it here:
| Adjacent holes measure | Your bolt pattern is |
|---|---|
| 2-5/8 in | 5x4.5 (most common) |
| 2-3/4 in | 5x4.75 |
| 3 in | 5x5 |
| 3-1/4 in | 5x5.5 |
Common trailer bolt patterns with metric equivalents
Listings sometimes show the same pattern in inches or millimeters. These are the same fitments:
| Inches | Metric | Typically found on |
|---|---|---|
| 4x4 | 4x101.6 mm | Small utility and boat trailers |
| 5x4.5 | 5x114.3 mm | Most light trailers, boat trailers, campers |
| 5x5 | 5x127 mm | Some utility and cargo trailers |
| 6x5.5 | 6x139.7 mm | Tandem-axle and heavier utility trailers |
| 8x6.5 | 8x165.1 mm | Heavy equipment and gooseneck trailers |
FAQ
Can I measure with the wheel still on the trailer?
Yes. The lug nuts mark the same circle as the holes — measure between lug nut centers using the same method for your lug count.
Is 5x4.5 the same as 5x114.3?
Yes. 4.5 inches equals 114.3 mm — one fitment, two ways of writing it.
My measurement falls between two sizes — which is it?
Re-measure from the centers of the holes, not the edges. The listed patterns are the standard sizes; a reading between them almost always means the tape drifted off center.
Does the new wheel need anything else to match?
Besides the bolt pattern, match the wheel diameter to your tire size and check the load rating covers your trailer's loaded weight per wheel.
Once you know your pattern, you can filter by lug count in our trailer wheels collection — every listing states its bolt pattern in inches and millimeters.