Nokian WR A4 245/40 R20

Nokian WR A4 is a winter tyre made in total of 59 sizes, ranging from R16 to R16 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. 245/40 R20 is 40mm wider than the narrowest dimension (205) and 0mm narrower than the widest one (245). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (245mm), which results in 98mm sidewall height.