US: 3.5–4.5 to Europe Size 44–45
Cross-market women’s sock and hosiery conversion mapping 3.5–4.5 specifications into 44–45.

Analyzing Women’s Sock Size Equivalence Across Markets
US: 3.5–4.5: Corresponds to a foot length range of 20–21.5 (7.9–8.5 ), US shoe size bracket of 3.5–4.5, and fit classification Snug / Petite Fit.
Europe Size 44–45: Corresponds to a foot length range of 27.5–29 (10.8–11.4 ), US shoe size bracket of 13–14.5, and fit classification Relaxed Stretch / Extended Fit.