For Road and Triathlon bikes it’s more common that the frame size is given in cm however occasionally the XXS to XXL notation is used so I have listed both.

For mountain bikes the XXS to XXL is more or less the standard now however some manufactures use inches as well but usually in addition.

Some manufacturers also list bike size my your inseam length, however unless your have unusually short or long legs the height reflects your inseam.

Your Size in cm Triathlon / Road MTB
148 – 152 47 – 48cm XXS XXS
153 – 160 49 – 50cm XS XS
161 – 168 51 – 53cm S S
169 – 175 54 – 55cm M M
176 – 183 56 – 58cm L L
184 – 191 59 – 60cm XL XL
192 – 198 61 – 63cm XXL XXL