Michelin Pilot Sport CUP 2 R 345/25 R21

Michelin Pilot Sport CUP 2 R is a summer tyre made in total of 37 sizes, ranging from R19 to R19 - this particular dimension is R21, which means it fits to a 21 inch/533.4mm diameter wheel. 345/25 R21 is 60mm wider than the narrowest dimension (285) and 0mm narrower than the widest one (345). This tyre profile of 25 means the sidewall height of the tyre is 25% of the tyre width (345mm), which results in 86.25mm sidewall height.