Calculate Tyre Dimensions for Plus Sizing/Up-Stepping
Enter the original tyre size and the new wheel size into the form below. The calculator will make a list of alternatives that have a diameter in the range of -3% to +4% of the difference between the outer tyre diameter and the wheel diameter (D-W). This formula is used by leading tyre manufacturers.
Tyre interchangeability is not always possible, so be sure to consult your car manufacturer's manual before changing your tyres. This is for informative purposes only.