US: 2XL (50–52) to United Kingdom Size 38–40

US: 2XL (50–52): Corresponds to a chest width of 127–132.1 $\text{cm}$ (50–52 $\text{in}$), neck collar girth of 47 $\text{cm}$ (18.5 $\text{in}$), sleeve length of 94 $\text{cm}$ (37 $\text{in}$), and fit style Extended Plus Fit.

United Kingdom Size 38–40: Corresponds to a chest width of 96.5–101.6 $\text{cm}$ (38–40 $\text{in}$), neck collar girth of 39.4 $\text{cm}$ (15.5 $\text{in}$), sleeve length of 86.4 $\text{cm}$ (34 $\text{in}$), and fit style Classic Regular Fit.