Usage:
Fill in the box(es) above with the original wheel specifications and hit "OK". This will produce a table to the right. The table shows different wheel sizes in the Y axis and different tire profiles in the X axis. In each row in each cell you will find the tire width and its approperiate wheel width for the tire that has about the same diameter as the original wheel.
In dark purple you find the diameters that are within 2% of the original, in light purple within 5% and in background color within 8%. Too weird tire dimensions aren't shown.