US: 9-11 to Europe Size 31-34
Cross-market children’s socks, tights, hosiery, leg warmers, and dance tights sizing conversion mapping 9-11 specifications into 31-34.

Analyzing Size Equivalence Across Markets
US: 9-11: Corresponds to a foot length of 23 (9.1 ), matching US shoe size 4-7, and age range 120–168 months.
Europe Size 31-34: Corresponds to a foot length of 20 (7.9 ), matching US shoe size 13-3, and age range 84–120 months.