US: 18-24M to Europe Size 80

US: 18-24M: Corresponds to a height baseline of 86 $\text{cm}$ (33.9 $\text{in}$), a weight baseline of 12 $\text{kg}$ (26.5 $\text{lbs}$), and a chest baseline of 53 $\text{cm}$ (20.9 $\text{in}$).

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 $\text{in}$).