US: 5–6.5 to Europe Size 38–40
Cross-market women’s sock and hosiery conversion mapping 5–6.5 specifications into 38–40.

Analyzing Women’s Sock Size Equivalence Across Markets
US: 5–6.5: Corresponds to a foot length range of 21.5–23 (8.5–9.1 ), US shoe size bracket of 5–6.5, and fit classification Comfort Stretch / Ankle Grip.
Europe Size 38–40: Corresponds to a foot length range of 23.5–25 (9.3–9.8 ), US shoe size bracket of 7–9.5, and fit classification Comfort Stretch / Ankle Grip.