Wheel Offset Calculator

See exactly how a new wheel + spacer combo moves your wheel inboard and outboard — before you buy.

Your setup

New setup

Spacers push the wheel outward = lower effective offset.

Width is stamped as e.g. "8.5J" and offset as "ET35" — usually on the back of a spoke or inside the barrel.

What changes (top-down view)

← strut (inner) fender (outer) →
current
new
hub mounting face

Illustration only — strut/fender positions vary by chassis, ride height, camber and tire. Always test-fit.

–
outer edge movement
–
inner edge movement
–
effective new offset
(with spacer)
Enter your numbersResults update live as you type.

How it works: outer movement = ½ width change − offset change; inner movement = ½ width change + offset change. Positive outer = more poke toward the fender; positive inner = closer to the strut. Spacers subtract from offset 1:1. This is a fitment estimator for a BMW chassis — suspension travel, camber, tire section width and fender liners all matter, so confirm with a test fit.

Built by Garage Tested — built. tested. documented.