Michelin Pilot Alpin PA4 345/25 R21

Michelin Pilot Alpin PA4 is a winter tyre made in total of 116 sizes, ranging from R17 to R17 - this particular dimension is R21, which means it fits to a 21 inch/533.4mm diameter wheel. 345/25 R21 is 120mm wider than the narrowest dimension (225) 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.