Existing setup
Enter existing and proposed tire sizes, wheel widths and ET.
Tire & Wheel Size Calculator
Compare tire sizes and wheel offset with diagrams, diameter, sidewall, rim shifts and theoretical speed changes. Free and local.
Open Tire & Wheel Size Calculator →Tire & Wheel Size Calculator
New setup
Compare nominal dimensions and signed rim-position changes.
Download report
Download report
Manlin services
Make space for what matters
Use Manlin to reflect, plan and take your next step.
Tire & Wheel Size Calculator FAQ
Will this confirm the wheels fit my car?
Nominal, unloaded geometry only. Tire stretch, load, brakes, suspension and vehicle clearance are not modeled.
What do positive rim shifts mean?
Positive outer shift means further outward. Positive inner shift means less room on the suspension side.
Why does the speed reading change?
Actual speed assumes the speedometer was calibrated to the existing tire; it scales with tire circumference.
How do I keep the results?
Download report
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