Wheel Offset Calculator

Wheel offset is measured in millimeters from the exact centerline of the wheel to the mounting surface that bolts up to the vehicle hub. Positive offset means the mounting pad is shifted toward the street side, while negative offset pushes it inward toward the vehicle suspension. To evaluate the change in inner clearance, the calculator first determines the distance from the hub mounting face to the inner edge of the old wheel using the formula: Inner Distance = (Width / 2) + Offset. It then computes the new inner distance and finds the Clearance Change by subtracting the new inner distance from the old inner distance. Similarly, outer stance changes are calculated by tracking the distance from the centerline to the outer rim edge.

Imagine you are upgrading your factory wheels to an aftermarket set. Your old wheels have a width of 7 inches (approx. 177.8 mm) and an offset of +40 mm. Your desired new wheels have a width of 8 inches (approx. 203.2 mm) and an offset of +30 mm. First, we calculate the old inner distance: (177.8 / 2) + 40 = 128.9 mm. Next, we find the new inner distance: (203.2 / 2) + 30 = 131.6 mm. The clearance change is 128.9 - 131.6 = -2.7 mm. This means your new inner wheel edge sits about 2.7 mm closer to your suspension struts, allowing you to verify if you have enough room to avoid rubbing.

Always measure your current wheel clearance with a physical ruler or gauge before ordering a new setup, especially if your car has aftermarket coil-overs or upgraded brake calipers. Keep in mind that changing your wheel offset drastically can alter your scrub radius, which affects steering feedback, suspension wear, and high-speed stability. Double-check whether your tire supplier lists overall section widths rather than nominal rim widths, as wider sidewalls can drastically reduce physical clearance regardless of offset calculations.