Caliper overhang: Is used to determine the clearance needed to the backside of the spokes of the wheel.
Caliper width: Used in conjunction with caliper overhang.
Radial Clearance: Caliper Radial Clearance
Hub Height: Height of hub diameter. If stepped, both heights required for accuracy.
Hub Diameter: sometimes has a step in it that requires both measurements to be accurate.
Length of Stud: Length of lug stud, Helpful if changed from factory
Stud Diameter:Wheel stud diameter
As a general rule: there should be a minimum of one-quarter inch (.250) clearance between the wheel and any braking or suspension component.
Having proper tire clearance is critical for a positive wheel/tire installation experience. There is no "cast in stone" rule to determine the proper amount of clearance between the tire and body of the car. There should be no less than what is required to avoid ALL contact between suspension and sheet metal in all driving situations.
Keep these in mind when measuring your car: