Wheel & tyre fitment calculator

Use our online tool to visualise different wheel and tyre options. Just enter the details of your current setup and new setup to get started.

Current setup

New setup


Speedo error0%-
Reading at 30mph30mph-
Reading at 60mph60mph-
Ride height--
Arch gap--

About our wheel fitment calculator

This calculator is designed to help you choose the optimum wheel and tyre combination for your car, taking in to consideration the tyre width, tyre profile, tyre diameter, wheel width and wheel offset.

It is important to understand that changing your wheel and tyre specifications from your manufacturers original specifications will affect how accurate your speedo will read. Please see the Speedo error section of the results for more details on this.

Understanding the different parameters

Tyre width

The tyre width is the measurement from a tyres inner sidewall to its outer sidewall in millimetres.

The wider the tyre, the more rolling resistence there is and therefore more grip - however, by using wider tyres you may notice a slighly increase in fuel consumption.

Tyre profile

The tyre profile is the height of the tyre's sidewall given as a percentage of its width.

For example, a tyre with a width of 200 and a profile of 40 will have a sidewall height of 80 (mm) - as 40% of 200 is 80.

Tyre diameter

The tyre diameter is quite simply the largest measurement of the cutout section of the tyre, from one side to the other. Therefore a 16 (inch) tyre will fit a 16 (inch) wheel rim.

Wheel width

The wheel width is the measurement of a wheel's cross-section, from one side to the other in inches.

Wheel offset

The wheel offset refers to how the wheel is mounted to your car's hub and is measured in millimetres.

An offset is either positive, negative or zero. An offset of zero means that the car's hub mounting surface is in the centre of the wheel rim. A positive offset will result in the hub being towards the front of the wheel, and a negative offset will result in the hub being toward the back of the wheel.