Continental ContiWinterContact TS 850P is a winter tyre made in total of 0 sizes, ranging from R to R - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. 255/45 R20 is 255mm wider than the narrowest dimension () and -255mm narrower than the widest one (). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (255mm), which results in 114.75mm sidewall height.