Wheel & tyre
calculator.
See what changes before you change your wheels.
Compare wheel position, tyre size and gearing with a clear view of the numbers.
Compare your setup.
Editable exampleEnter the sizes marked on your wheels and tyres.
Wheel width is the nominal bead-seat width. ET is offset in millimetres.
Nominal tyre envelope and bead-seat rim dimensions. Actual tyre shape, stretch and wheel lip are not shown.
Check your measurements.
Enter valid measurements in both setups to see the comparison.
The difference.
—
Further out towards the arch.
Measured at the nominal rim edge.—
Less room on the inside.
Relative to the current wheel position.—
Car sits higher. Arch gap reduces by this amount.
From tyre size alone, with suspension unchanged.| Measurement | Current | Proposed | Change |
|---|---|---|---|
| Sidewall height | — mm | — mm | — mm |
| Tyre diameter | — mm | — mm | — mm |
| Circumference | — mm | — mm | — mm |
At an indicated
— mph
With the proposed tyres, assuming the current speed reading is accurate.
Rolling circumference comparison.See this setup on your car.
Take these dimensions into the visualiser. Add your photo and choose a STRAKE wheel.
The numbers are
one part of it.
This compares geometry. It does not confirm that a wheel or tyre will fit your car.
What else needs checking?
Body and suspension clearance through steering and suspension travel, brake and spoke clearance, tyre-to-rim suitability, load and speed ratings, PCD, centre bore, fixings and spacer suitability all need to be checked separately.
Tyre dimensions are calculated from the marked size. Actual dimensions vary by tyre, rim and load. Ride height and arch-gap changes shown are theoretical changes from tyre radius alone; suspension, camber and tyre deflection are not modelled. A small percentage change is not a fitment approval.
How the comparison works
Width and diameter are converted from inches to millimetres. Offset locates the wheel centre relative to its mounting face; a spacer reduces the effective offset. The calculator compares the nominal inner and outer rim positions, and calculates tyre sidewall, diameter and circumference from the tyre marking.
The link you choose to copy contains only the calculator measurements and display settings. This tool does not save your car details or use a vehicle lookup.