Avon ZX7 275/45 R21

Avon ZX7 is a summer tyre made in total of 67 sizes, ranging from R13 to R13 - this particular dimension is R21, which means it fits to a 21 inch/533.4mm diameter wheel. 275/45 R21 is 60mm wider than the narrowest dimension (215) and 20mm narrower than the widest one (295). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (275mm), which results in 123.75mm sidewall height.