United Kingdom Size 42 to US: 36

United Kingdom Size 42: Corresponds to a waist size of 105 $\text{cm}$ (42 $\text{in}$), total strap length of 120 $\text{cm}$ (47.2 $\text{in}$), and recommended fit classification Relaxed / Comfortable.

US: 36: Corresponds to a waist size of 90 $\text{cm}$ (36 $\text{in}$), total strap length of 105 $\text{cm}$ (41.3 $\text{in}$), and recommended fit classification Standard / Regular.