US: 4-7Y to Europe Size 41-43
Cross-market children’s hats, beanies, caps, sun hats, and ear-flap hats apparel conversion mapping 4-7Y specifications into 41-43.

Analyzing Size Equivalence Across Markets
US: 4-7Y: Corresponds to a head circumference baseline of 53 (20.9 ) and age range 48–84 .
Europe Size 41-43: Corresponds to a head circumference baseline of 42.5 (16.7 ) and age range 3–6 .