US: 13.5–15 to United Kingdom Size 8–10
Cross-market men’s sock conversion mapping 13.5–15 specifications into 8–10.

Analyzing Sock Size Equivalence Across Markets
US: 13.5–15: Corresponds to a US shoe size range of 13.5–15, foot length of 30.5–32 (12–12.6 ), and fit classification Extended Volume / High Stretch.
United Kingdom Size 8–10: Corresponds to a US shoe size range of 8.5–10.5, foot length of 26.5–28 (10.4–11 ), and fit classification Standard Regular Fit.