United Kingdom Size 6 to US: S

United Kingdom Size 6: Corresponds to a waist/hip size of 70 $\text{cm}$ (28 $\text{in}$), waist range of 60–70 $\text{cm}$ (23.6–27.6 $\text{in}$), total strap length of 80 $\text{cm}$ (31.5 $\text{in}$), and fit classification Waist / Snug Cinch.

US: S: Corresponds to a waist/hip size of 75 $\text{cm}$ (30 $\text{in}$), waist range of 66–76 $\text{cm}$ (26–29.9 $\text{in}$), total strap length of 85 $\text{cm}$ (33.5 $\text{in}$), and fit classification Standard Waist / Hip.