United Kingdom Size 38-40 to US: 42-44

United Kingdom Size 38-40: Corresponds to a relaxed chest range of 98–102 $\text{cm}$ (38.6–40.2 $\text{in}$), elastic waist range of 84–90 $\text{cm}$ (33.1–35.4 $\text{in}$), and fit classification Relaxed / Comfort Fit.

US: 42-44: Corresponds to a relaxed chest range of 106–110 $\text{cm}$ (41.7–43.3 $\text{in}$), elastic waist range of 92–98 $\text{cm}$ (36.2–38.6 $\text{in}$), and fit classification Relaxed / Comfort Fit.