Wheel Offset Calculator
Calculate the inner clearance and outer position change when switching to wheels with different width and offset (ET). Includes a guide to positive, zero, and negative offset.
Current Wheel
New Wheel
Wheel Fitment Change
+2.7 mm outer
Inner Change
+22.7 mm
Backspacing Change
+2.7 mm
โ ๏ธ Wheel pokes 2.7mm further out. Check fender clearance.
๐ก How to Use the Wheel Offset Calculator
Understanding Wheel Offset
Wheel offset (measured in millimeters, abbreviated ET from the German "Einpresstiefe") is the distance from the wheel's mounting face to its geometric centerline.
Types of Offset
| Type | Range | Appearance |
|---|---|---|
| Positive (+) | +15 to +55mm | Wheel sits flush or slightly inside fender |
| Zero (0) | 0mm | Mounting face at exact center |
| Negative (โ) | โ10 to โ44mm | Wheel pokes outward past fender |
What Happens When You Change Offset
Lower offset (more negative): The wheel moves outward โ more aggressive stance, potential fender contact, increased steering effort, and added stress on wheel bearings.
Higher offset (more positive): The wheel moves inward โ more clearance from fenders, but potential contact with suspension components and brakes.
Backspacing Explained
Backspacing is the distance from the back edge of the wheel to the mounting face. It's related to offset but accounts for wheel width: Backspacing = (Width รท 2) + Offset. Wider wheels with the same offset have more backspacing.