How to Measure your Trailer Wheels Bolt Pattern

Measure Trailer Wheel Bolt Pattern

In order to find the right wheel for your trailer, you will need to know the bolt pattern. Trailer wheel bolt patterns can be defined by the number of bolts or lugs per wheel and the diameter of the circle that the bolts are arranged on. Figuring out the right bolt pattern is rather simple, but it is extremely important that the measurements are accurate. Most trailers on the road have a 4, 5 or 6 Lug pattern. A very common designation for a trailer wheel would be 5 on 4.5. This means that the hub has 5 bolts spaced evenly on a 4-1/2" circle (see 5-lug diagram).

1. Count the number of lugs one trailer wheel. Most trailer wheels have 4 or 5 lugs per wheel. Larger heavy duty trailers generally have 6 or 8 Lugs per wheel.
   
2. If the trailer wheel has an even number of lugs, measure from the center of one bolt to the center of the bolt directly opposite using a tape measure or ruler. The bolt pattern will be determined by the number of lugs and the distance between the opposing lug (see 4-lug hub diagram). All but the 5-lug bolt patterns are measured this way.
   
3. If your trailer wheel has 5 lugs, measuring is a little different. Find any lug and measure the distance between the back edge of one lug to the center of another one directly across from it. It is important to skip one bolt when measuring.

	Measure a 4 lug trailer wheel from the middle of one hole to the middle of the hole directly across from it. You can also measure a 6 or 8 lug wheel in the same way.
	Measure a 5 lug trailer wheel from the back of one hole to the middle of the hole directly across from it.