United Kingdom Size 16–18 to US: S (4–6)

United Kingdom Size 16–18: Bust interval range of 97.8–104.1 $\text{cm}$ (38.5–41 $\text{in}$), natural waist range of 76.2–82.6 $\text{cm}$ (30–32.5 $\text{in}$), shoulder width of 41.3 $\text{cm}$ (16.25 $\text{in}$), sleeve length of 80 $\text{cm}$ (31.5 $\text{in}$), style variants Blouses, T-Shirts, Tank Tops, Sweaters & Cardigans, and fit classification Relaxed Comfort Fit.

US: S (4–6): Bust interval range of 86.4–90.2 $\text{cm}$ (34–35.5 $\text{in}$), natural waist range of 64.8–68.6 $\text{cm}$ (25.5–27 $\text{in}$), shoulder width of 38.1 $\text{cm}$ (15 $\text{in}$), sleeve length of 77.5 $\text{cm}$ (30.5 $\text{in}$), style variants Blouses, T-Shirts, Tank Tops & Sweaters, and fit classification Slim Tailored Fit.