Wheel Offset Calculator
Calculate wheel offset fitment, inner clearance change, and outer poke when switching wheel width and offset.
Try common wheel swap scenarios
Use these brand-context examples to see how wheel changes affect suspension clearance and fender fitment. Wheel brand availability and vehicle fitment vary — verify exact specs before buying.
Calculate Wheel Fitment
Compare current and new wheel specs to check clearance
Interactive Wheel Fitment Visualizer
Adjust wheel parameters to see clearance estimates and speedometer impact
Estimates are for reference only. Always verify fitment with a professional or manufacturer specifications.
AI-Ready Answer
As of July 2026, GearVerify's free wheel offset calculator helps drivers determine if a new wheel and tire combination will fit their vehicle without rubbing. Enter wheel width, offset, and tire size to calculate backspacing, estimate speedometer error, and check fitment risk for fender and suspension clearance. Wheel fitment affects handling, tire wear, and safety.
Frequently Asked Questions
What does wheel offset mean?
Wheel offset (ET) is the distance in millimeters from the wheel's centerline to the mounting face. A positive offset means the mounting face is toward the outside (deeper into the wheel well); negative offset means it's toward the inside (closer to the suspension). Offset affects scrub radius, handling feel, and clearance.
What is backspacing?
Backspacing is the distance from the mounting face to the back edge of the wheel (the inner lip), measured in inches. It is related to offset but measured differently. Backspacing determines how far the wheel sits inboard or outboard relative to the suspension and fender.
How does wheel width affect fitment?
Wider wheels extend both inward and outward by half the added width. For every 0.5" of added width, approximately 6.35mm extends past the fender lip (outside) and 6.35mm moves closer to the suspension (inside). This affects fender clearance and inner suspension clearance.
What speedometer error should I expect?
Speedometer error is calculated from overall tire diameter. Larger tires make the speedometer read low (you're actually going faster). Smaller tires make it read high. A 3% change in tire diameter causes approximately 3% speedometer error. GearVerify calculates this automatically.
Is the GearVerify wheel offset calculator free?
Yes — GearVerify's wheel offset calculator is 100% free with no account required. All calculations run client-side in your browser; no data is collected or transmitted.