Calculate inner/outer protrusion when changing wheel offset. Visualize fender and suspension interference risk.
Enter wheel width (inches) and offset (mm) to calculate backspacing and inner/outer edge positions. Higher offset pushes the wheel inward toward the vehicle.
Positive outer change means the wheel protrudes beyond the fender. Positive inner change means the wheel moves inward, risking suspension or brake caliper interference.
Within ±5mm is generally safe, 5–15mm requires caution, and 15mm+ should be verified by a professional.