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.
8connected tools
0accounts needed
1shareable result
Start with the answer you need.
Every tool uses the same clear design, responsive results, and transparent assumptions.
Wheel Fitment Calculators
Wheel & Tire Fitment
Compare complete current and proposed wheel-and-tire setups, including tire geometry, wheel position, ride-height change and speed effect.
Open calculatorWheel Offset & Backspacing
Convert offset and backspacing or compare how wheel width and offset change nominal inner and outer position.
Open calculatorWheel Spacer
Calculate effective offset, outward wheel movement, inner clearance gained and axle track change after adding a spacer.
Open calculatorWheel Poke & Clearance
Compare two wheel widths and offsets to see theoretical outer poke change and suspension-side clearance change.
Open calculatorTire Sizing Calculators
Tire Size Comparison
Compare sidewall height, diameter, circumference, radius and revolutions per mile or kilometre for two tire sizes.
Open calculatorTire Size Converter
Convert metric tire dimensions to inch-style dimensions, or estimate metric geometry from flotation-style sizes.
Open converterPlus Sizing
Explore dimensional tire candidates for larger wheel diameters while keeping theoretical overall diameter close to the starting tire.
Open calculatorSpeed & Dimensions
Which calculator should I use?
Changing wheels and tires together?Use the full fitment comparison →
Adding a spacer?Calculate effective offset →
Checking how far a wheel moves?Compare poke & inner clearance →
Only comparing tire dimensions?Compare tire sizes →
Dimensional estimates, not a fitment guarantee
These tools compare nominal measurements. They cannot verify vehicle-specific brake, suspension, hub, fender, load-rating, or legal requirements.