Backspacing vs. Offset

[dhansell22]

??

[asepgrad98]

Wheel Backspace

This is the distance from the back edge of the wheel to the hub mounting surface.

 

Wheel Offset

The wheel's offset is the distance from its hub mounting surface to the centerline of the wheel.

[mdub]

Here's a picture:

 

Offset/Backspace Diagram

 

Weld Racing used to have a better picture on their website, but I can't locate it.

[dhansell22]

So it seems they are directly related. The reason I ask is I need 4-4.5" backspace for my lift. Nothing mentioned about offset but in looking at wheels online I see offset choices of -6mm etc.