Pirelli P ZERO Corsa 325/30 R21

Pirelli P ZERO Corsa is a summer tyre made in total of 34 sizes, ranging from R19 to R19 - this particular dimension is R21, which means it fits to a 21 inch/533.4mm diameter wheel. 325/30 R21 is 100mm wider than the narrowest dimension (225) and 0mm narrower than the widest one (325). This tyre profile of 30 means the sidewall height of the tyre is 30% of the tyre width (325mm), which results in 97.5mm sidewall height.