The offset of a wheel is the distance from the hub mounting surface to the centre line of the wheel. The wheel offset is measured in millimetres.
There are three types of offset – zero offset, positive offset, and negative offset.
Backspacing: Backspacing refers to how much space there is between the back side of the wheel and the mounting surface of the wheel.
Zero Offset: In a wheel with zero offset, the mounting surface of the wheel is on the centerline. The centerline is the centermost point of your wheel, if you were cutting it in half vertically.
Positive Offset: In a wheel with positive offset, the mounting surface of the wheel is to the outside of the wheel (on the street side). This is the most common scenario for newer, OEM setups. This offers maximum backspacing.
Negative Offset: In a wheel with negative offset, the mounting surface of the wheel is tucked back closer to the inside edge of the wheel, offering less backspacing, and a more “dished” wheel, popular in show cars and trucks.
