US: Newborn to Europe Size 49-51
Cross-market children’s hats, beanies, caps, sun hats, and ear-flap hats apparel conversion mapping Newborn specifications into 49-51.

Analyzing Size Equivalence Across Markets
US: Newborn: Corresponds to a head circumference baseline of 36 (14.2 ) and age range 0–1 .
Europe Size 49-51: Corresponds to a head circumference baseline of 50 (19.7 ) and age range 24–48 .