1. What is Wheel Offset?

Wheel offset is the distance between the wheel's mounting surface and its centerline, measured in millimeters. It determines how far in or out your wheels sit in the wheel wells.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( \text{new\_offset} \) — Offset of the new wheel (mm)
• \( \text{old\_offset} \) — Offset of the original wheel (mm)
• \( \text{offset\_diff} \) — Difference in wheel position (positive = sits further out, negative = sits further in)

3. Importance of Offset Calculation

Details: Correct wheel offset is crucial for proper vehicle handling, preventing rubbing against suspension components, and maintaining correct scrub radius.

4. Using the Calculator

Tips: Enter both offsets in millimeters. Positive offset means the mounting surface is toward the front (street) side of the wheel. Negative offset means it's toward the back (brake) side.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical offset range?
A: Most passenger cars have +35mm to +45mm offset. SUVs may have +15mm to +30mm. Negative offsets are common on trucks and custom wheels.

Q2: How much offset change is safe?
A: Generally, ±5mm is safe for most vehicles. Larger changes may require suspension modifications or fender rolling.

Q3: Does offset affect tire wear?
A: Yes, incorrect offset can cause uneven tire wear and accelerated bearing wear due to altered suspension geometry.

Q4: What's the difference between offset and backspacing?
A: Backspacing measures from the mounting surface to the inner edge, while offset measures from the mounting surface to the centerline.

Q5: Can I use this for wheel spacers?
A: Yes, wheel spacers effectively reduce offset. A 10mm spacer on a +40mm wheel gives an effective +30mm offset.