Wheel Offset Calculator - Rim Fitment Tool

Wheel offset is the distance from the wheel's centerline to the hub mounting surface, measured in millimeters. Positive offset means the mounting surface is toward the front (street side), negative offset pushes the wheel outward. This calculator converts between offset and backspacing.

1. 1

   Choose Calculation Mode

   Select whether to calculate from offset or from backspacing

2. 2

   Enter Wheel Width

   Input wheel width in inches (e.g., 8.5 inches)

3. 3

   Enter Offset or Backspacing

   Provide offset in mm or backspacing in inches

4. 4

   View Fitment Data

   See calculated measurements and fitment information

• 1

  Stay within 5-10mm of stock offset for daily drivers to maintain handling

• 2

  Lower offset (more negative) pushes wheels outward for wider stance

• 3

  Always check both inner clearance (suspension/brakes) and outer clearance (fenders)

• 4

  Consider tire width as it affects total package clearance beyond wheel offset

• 5

  Test fitment at full steering lock and suspension compression before committing

• Confusing offset with backspacing - they reference different points

• Not accounting for tire width when calculating total package fitment

• Changing offset without checking brake caliper and strut clearance

• Ignoring the effect of offset changes on handling and scrub radius