Wheel Offset Calculator
Changing wheels moves the tire in or out — even if the tire size stays the same. Enter your current and new setups and see exactly how much closer the tire gets to the suspension, and how much further it pokes out of the fender.
Current setup on the vehicle now
New setup you are considering
Gray = your current setup, orange outline = the new one. The blue dashed line is the hub mounting face; everything is drawn to the same scale from your numbers. The dashed gray and orange lines mark the old and new inner edges — the gap that decides inside rubbing.
How offset works
Offset (ET) is the distance in millimeters between the wheel's mounting face and its centerline. Positive offset tucks the wheel in toward the suspension; negative offset pushes it out toward the fender. Wheel width matters too: a wider wheel spreads the tire's beads, and the section sits a little wider. This calculator positions the tire from three numbers per side — tire section width, wheel width and offset — measured from the hub mounting face, which is the one reference point that never moves.
What these numbers can and cannot say
They tell you exactly how the tire's edges move. They cannot tell you whether it will rub: that depends on the room your vehicle actually has. Measure your tightest inner gap (inner sidewall to suspension, wheels at full lock) and compare it with the inner-edge change above — if the tire moves in by more than the gap you measured, expect contact. The five-minute measuring guide walks through it, and the size comparison tool covers the diameter side of the same question.
Can I change offset without changing tire size?
Yes — wheels alone reposition the tire. Going from ET+25 to ET−12 on the same tire moves the whole tire 37 mm outward: 37 mm more room inside, 37 mm more poke outside. Run it above with the same size on both sides.
Does a wider wheel change where the tire sits?
The centerline stays where the offset puts it, but a wider wheel stretches the tire slightly wider and can change the section shape a little. The position math above uses the tire's nominal section width, which is the neutral reference.
Method and data notes: how every number here is calculated. Last verified November 12, 2026.