Off set wheel questions

[da King]

The off set is to clear the calipers, suspension parts? Correct? How is it measured, how do you check? Can someone explain off set wheels to me.
Thanks
Finn

[Bob_n_Cincy]

offset.jpg
It is the distance from the center of the tire to the mounting surface.
It is 55 in the attached picture.
Bob

[Xusia]

What Bob said, plus this: Together with the wheel width, the offset determines the wheel's lateral position within the wheel well. In other words, it affects how far in or out a wheel sticks from the wheel well. Additional positive offset positions the wheel further in (potentially causing interference with parts located there like lower control arms, shocks, etc.), whereas lower positive offsets position the wheel further out.

Offset probably won't help much with brake clearance - wheel diameter probably has more to do with that.

I hope this helps.

[Goldwing]

What they said^^, it's just another way to express back spacing and frontspacing. Keep in mind since offset is measured from the wheel centerline, the same number offset in a different width wheel will not fit the same. In the same offset, a wider wheel will have additional backspacing and frontspacing. Just an easy mistake to make.