Calculates the diameter, width, sidewall, circumference, and revolutions per mile/km of any tire. Just enter the tire size. Compare two different tyre sizes and see the differences right away. "Tire Size" is not only a tire size calculator. It has a comprehensive database of the most famous tire brand and model of tires for choose. Using the calculator, you can see what's the difference in tire width, radius, diameter, circumference and vehicle actual speed after changing of tire and wheel size in very simple and clear graphical view.