US: 3.5–4.5 to Europe Size 41–43
Cross-market women’s sock and hosiery conversion mapping 3.5–4.5 specifications into 41–43.

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 41–43: Corresponds to a foot length range of 25.5–27.5 (10–10.8 ), US shoe size bracket of 10–12.5, and fit classification Comfort Stretch / Ankle Grip.