Wheel Fitment Assistant
Compare wheel offset, rim width and tyre size to see how your new setup changes fitment.
Wheel Finder
Choose diameter, width, bolt pattern, then offset. Each step shows only matching specifications.
Wheel and Tyre Comparison
Existing setup
New setup
Copy this comparison manually:
Your results
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More measurements
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* Rim positions use nominal bead-seat width, not measured flange width or backspacing.
Speed assumes calibration to the existing tyre. Ride-height and arch-gap changes are nominal.
Illustrative designs only. Changing style never changes your measurements.
View the five sample designs
Compare dimensions, not guaranteed clearance. The brake and strut are illustrations, not your vehicle's measurements. Tyre contours, wheel barrels and spoke shapes are schematic. This tool does not confirm brake, suspension or guard clearance, tyre-to-rim suitability, or road legality.
How to read this comparison
Further out means the nominal outer rim edge moves toward the outside of the car. It does not establish where your guard is.
Further in means the nominal inner rim edge moves toward the suspension. Actual remaining clearance requires a measurement of your current setup.
Offset and spacers position the rim relative to the fixed vehicle hub. Effective ET = wheel ET minus spacer thickness. Offset changes the fitment diagram, not the wheel-face design.
Wheel appearance compares nominal rim diameter, tyre diameter and sidewall proportion. The style artwork is not a manufacturer CAD model; concavity and brake clearance are not modelled.
Nominal tyre diameter = wheel diameter in inches × 25.4 + 2 × tyre width × profile / 100. This is an unloaded size estimate, not measured rolling circumference.
Side-by-side uses the same scale for both setups. On small screens the two views stack vertically without individually rescaling either wheel.
Wheel offset and tyre size calculator
Use the RevRunners Wheel Fitment Assistant to compare your existing wheels and tyres with a new setup. Enter tyre width, aspect ratio, wheel diameter, rim width and offset for each setup. Add spacer thickness if needed, then compare the front and rear axles independently.
What the comparison shows
The diagram shows how the nominal inner and outer rim positions move relative to the hub. The results compare tyre diameter, circumference, sidewall height and nominal ride-height change. The speed comparison assumes your speedometer was calibrated to the existing tyre size.
What does wheel offset change?
Offset is the distance between the wheel centreline and its mounting face. For the same rim width, reducing positive offset moves the wheel further outward. A spacer reduces effective offset by its thickness. Changing rim width also changes both inner and outer positions.
Does this confirm that wheels fit my car?
No. The calculator compares nominal dimensions. Brake caliper, suspension and guard clearance depend on your vehicle, wheel design and measured space. Tyre dimensions also vary by manufacturer and measuring rim. Check those details before ordering.
Do the wheel styles change the calculations?
No. The five wheel styles are illustrative appearance references. They do not select products or prove availability in your entered size.
Use the Wheel Finder above to browse by diameter, width, bolt pattern and offset, or contact our team for help checking a specific wheel and vehicle.
Ask about wheel fitment