Please select your Tyre Width. This is generally the first set of numbers found on your tyre side wall and represents the overall width (in mm) of the tyre when inflated to recommended tyre pressure.

The Aspect Ratio is the percentage ratio of the width of the tyre to it's height. You can generally find this on the tyre side wall and is the number recorded after the '/'

Please select your Rim Diameter. This is generally the number found after the letter R in your tyre size and represents the size of the Wheels fitted to your vehicle.