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

United Kingdom Size 4–6: Bust interval range of 80–85 $\text{cm}$ (31.5–33.5 $\text{in}$), natural waist range of 58.4–63.5 $\text{cm}$ (23–25 $\text{in}$), shoulder width of 36.8 $\text{cm}$ (14.5 $\text{in}$), sleeve length of 76.2 $\text{cm}$ (30 $\text{in}$), style variants Tank Tops, Camisoles, Slim T-Shirts & Fitted Sweaters, and fit classification Petite Contour Fit.

US: XL (16–18): Bust interval range of 105.4–111.8 $\text{cm}$ (41.5–44 $\text{in}$), natural waist range of 83.8–90.2 $\text{cm}$ (33–35.5 $\text{in}$), shoulder width of 43.2 $\text{cm}$ (17 $\text{in}$), sleeve length of 81.3 $\text{cm}$ (32 $\text{in}$), style variants Relaxed Blouses, T-Shirts, Sweaters & Tunics, and fit classification Generous Full Fit.