How to Measure a 5 Lug Trailer Axle Bolt Pattern

Measuring Methods

Measure a 5-lug trailer axle bolt pattern using one of two primary methods to ensure wheel compatibility. The industry standard is 5 on 4.5 inches (5×4.5″), common for 3,500 lb axles, with 5 on 5″ (5×5″) as the secondary option.​

Method 1: Adjacent Centers
Measure from the center of one lug stud to the center of the adjacent stud. Common measurements include:

• 2 5/8″ for 5 on 4.5″​​

• 2 3/4″ for 5 on 4.75″​​

• 3″ for 5 on 5″​​

• 3 1/4″ for 5 on 5.5″​​

Method 2: Skip-One Cross Measure
Measure from the outer edge of one lug stud, skip the next stud, to the center of the third stud. This yields the full bolt circle diameter directly, such as 4.5″ for the standard pattern, and works well even with the wheel mounted.​​

Tips for Accuracy

Use a tape measure or caliper for precision, ideally with the wheel on or off the hub for access. Consider a plastic 5-lug bolt pattern template for quick verification of common sizes like 4.5″, 4.75″, 5″, or 5.5″. Always confirm before ordering axles or wheels to avoid mismatches.​​