When upgrading your vehicle’s wheels to custom ones, it’s crucial to consider the wheel offset. This parameter determines how the wheel aligns with the suspension and affects factors like clearance and position. This guide provides insights into wheel offset, its calculation, and the use of a wheel offset calculator.

Key Wheel Terms

  1. Declared Width or Rated Width: Inner distance between the walls of the bead seat where the tire sits.
  2. Overall Wheel Width: Complete width of the wheel, including the walls or flanges on either side.
  3. Centreline: The line dividing the wheel’s cross-section into two halves.

What is Wheel Offset?

Wheel offset is the distance between the mounting pad (where the wheel aligns with the hub) and the centerline of the wheel. A positive offset means the wheel is outward, while a negative offset brings it closer to the suspension.

Calculating Wheel Offset

To calculate wheel offset for a new wheel:

  1. Enter the width and offset of the current wheel.
  2. Input the width and offset of the new wheel.
  3. The calculator provides the change in clearance and position.

Example Calculation


  • Current Wheel: 7 in. width, 42 mm offset
  • New Wheel: 8 in. width, 32 mm offset


  • Clearance Change: -2.7 mm
  • Position Change: -22.7 mm

Negative values indicate the new wheel is closer to the suspension, reducing clearance.

Frequently Asked Questions

  1. What is Wheel Offset?
    • Wheel offset is the distance between the wheel’s centerline and the mounting pad. It can be positive, negative, or zero.
  2. How to Calculate Clearance Change?
    • Subtract the width of the new wheel from the current wheel, divide by two, and add the offset difference.
  3. What is Wheel Backspacing?
    • Wheel backspacing is the distance between the mounting pad and the inner lip. It indicates the pad’s location relative to the wheel width.
  4. Types of Offsets?
    • Offsets can be positive, negative, or zero, signifying the mounting hub’s position relative to the suspension.
  5. Clearance for 2 mm Difference in Width and Offsets?
    • The clearance change is 3 mm for a 2 mm difference, calculated as (Difference/2) + 1.


Understanding wheel offset is crucial for customizing wheels. The calculator simplifies the process, ensuring optimal performance and preventing interference issues. Consider these factors to enhance your vehicle’s aesthetics and functionality.