Fitment toolkit
Wheel & tire calculators built for clearer decisions.
Use the complete comparison for an end-to-end fitment check or choose a focused calculator for a single question.
4connected tools
0accounts needed
1shareable result
Start with the answer you need.
Every tool uses the same clear design, responsive results, and transparent assumptions.
Wheel & Tire Fitment
Compare current and proposed wheel-and-tire dimensions, rim position, ground-clearance change, and estimated speedometer impact.
Open calculatorWheel Offset & Backspacing
Convert offset and backspacing or compare how two wheel widths and offsets change nominal inner and outer position.
Open calculatorTire Size Comparison
Compare sidewall height, diameter, circumference, radius, and revolutions per mile or kilometre for two tire sizes.
Open calculatorSpeedometer Error
Estimate how a tire-diameter change affects actual speed at a selected indicated speed and across a reference table.
Open calculatorDimensional estimates, not a fitment guarantee
These tools compare nominal measurements. They cannot verify vehicle-specific brake, suspension, hub, fender, load-rating, or legal requirements.