Wheel Offset Calculator

Wheel offset (ET) is the distance in millimeters from the wheel's center line to its mounting surface. Positive offset means the mounting surface is toward the outside of the wheel (common on FWD cars). Negative offset means it is toward the inside (common on trucks). Zero offset means the mounting surface is at the center line.

Generally, a change of 5-10mm from stock is safe for most vehicles. Changes beyond 15mm may cause rubbing on fenders or suspension components. Wider wheels with lower offset push the tire outward, which can affect handling and put stress on wheel bearings.

Wheel spacers push the wheel outward from the hub, effectively reducing the offset. A 15mm spacer on an ET45 wheel makes it behave like an ET30 wheel. This creates a wider stance but can stress bearings if overdone. Always use hub-centric spacers for safety.