US: 6-9M to Europe Size 80

US: 6-9M: Corresponds to a height baseline of 68 $\text{cm}$ (26.8 $\text{in}$), a weight baseline of 8 $\text{kg}$ (17.6 $\text{lbs}$), and a chest baseline of 47 $\text{cm}$ (18.5 $\text{in}$).

Europe Size 80: Corresponds to a height baseline of 80 $\text{cm}$ (31.5 $\text{in}$), a weight baseline of 11 $\text{kg}$ (24.2 $\text{lbs}$), and a chest baseline of 52 $\text{cm}$ (20.5 $\text{in}$).