US: 4XL to United Kingdom Size 18

US: 4XL: Corresponds to a waist/hip size of 105 $\text{cm}$ (42 $\text{in}$), waist range of 97–107 $\text{cm}$ (38.2–42.1 $\text{in}$), total strap length of 115 $\text{cm}$ (45.3 $\text{in}$), and fit classification Expanded / Plus.

United Kingdom Size 18: Corresponds to a waist/hip size of 95 $\text{cm}$ (38 $\text{in}$), waist range of 86–97 $\text{cm}$ (33.9–38.2 $\text{in}$), total strap length of 105 $\text{cm}$ (41.3 $\text{in}$), and fit classification Relaxed Waist / Hip.