How To Understand Wheel Specs

Choosing new wheels is an exciting part of a build. Aside from paint, it’s what makes your ride stand out the most. The first step to choosing new wheels is, of course, the design, but it doesn’t stop there. You then have to decide what size you want between width, bolt pattern, and offset. So here’s a crash course on what all those numbers mean.

• OEM Factory Option Look-up: Wheel and Tire Size

Wheel Width

When measuring for wheel diameter, you aren’t measuring the physical size of the wheel, but instead, the surface that the bead of the tire mounts to.

The same thing applies to the measuring wheel width.

Bolt Pattern

When it comes to bolt pattern, the first number is the number of bolt holes in the wheel itself. The second number is the diameter of an imaginary circle in inches or millimeters that runs through the center of each of the studs.

• How To Measure Wheel Bolt Pattern

This is easy on a 4, 6, 8, or 10-lug wheel as you just measure from the center of one stud to the center of the stud directly across from it. However, on a 5-lug wheel, you can’t do that since no two studs are directly across from each other. You’ll have to measure from the center of one lug to the outside edge of a hole that’s across from it.

• Wheel Bolt Pattern Cross-reference ~ Look up bolt pattern by vehicle, or by bolt pattern to determine which vehicles share wheels.

Backspacing and Offset

Next up, backspacing and offset. That refers to how far in the hub-mounting surface is from the back surface of the wheel. To measure backspacing simply take a straight edge, lay it across the back of the wheel and take your measurement. Offset is slightly different as it has to do with the centerline of the wheel.

• How To Measure Wheel Back Spacing / Offset

If the hub mount is towards the outside of the wheel it will have a positive offset. Likewise, if it’s towards the inside of the wheel it will have a negative offset…