How is Wheel Bolt Pattern Determined for Trailers

Question:

I have a Boat Trailer that has 6.50x13 tires on it. The wheel is a 5 lug mount. So when you mentioned that a wheel is 5 on a 41/2 bolt pattern. What does the 4 1/2 mean to me?

asked by: John T

Expert Reply:

The bolt pattern of a wheel is defined by two numbers: the number of bolt holes and the diameter of the circle (in inches) that they form, measured through the centers of the bolt holes. For example, a 5 on 4-1/2 bolt pattern defines a wheel that has 5 bolt holes spaced out evenly along a circle that has a 4-1/2" diameter.

I attached a picture and a help article that details how to determine bolt pattern.

expert reply by: Jameson C