United Kingdom Size Classic to US: Slim / 49mm

United Kingdom Size Classic: Corresponds to a nominal width of 53 $\text{mm}$ (2.09 $\text{in}$), length of 190 $\text{mm}$ (7.48 $\text{in}$), average structural girth of 106 $\text{mm}$ (4.17 $\text{in}$), and fit category Standard / Original.

US: Slim / 49mm: Corresponds to a nominal width of 49 $\text{mm}$ (1.93 $\text{in}$), length of 175 $\text{mm}$ (6.89 $\text{in}$), average structural girth of 98 $\text{mm}$ (3.86 $\text{in}$), and fit category Snug / Close.