Measured in millimetres.
The height of the sidewall as a percentage of its width.
Actually redundant - 'R' stands for 'Radial', as the majority of modern tyres are.
Wheel rim diameter
Measured in inches, the diameter of the rim wheel has been designed to fit. Measured bead shoulder to bead shoulder.
An index of potential weight, rather than an actual measurement. A load index of 88 corresponds to 560kg. The full index can be found on Protyre’s website.
A second index for speed ratings. Confusingly, not strictly alphabetical: ‘H’ appears between ‘U’ and ‘V’. ‘H’ rated tyres can be used up to 130mph