United Kingdom Size 3.5–5 to US: 4–5.5
Cross-market men’s sock conversion mapping 3.5–5 specifications into 4–5.5.

Analyzing Sock Size Equivalence Across Markets
United Kingdom Size 3.5–5: Corresponds to a US shoe size range of 4–5.5, foot length of 22–23.5 (8.7–9.3 ), and fit classification Snug / Compact Fit.
US: 4–5.5: Corresponds to a US shoe size range of 4–5.5, foot length of 22–23.5 (8.7–9.3 ), and fit classification Snug / Compact Fit.
Other Conversions to US: 4–5.5
United Kingdom Size 3.5–5 → us-4-5-53.5–5 to us-4-5-5
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United Kingdom Size 5.5–7.5 → us-4-5-55.5–7.5 to us-4-5-5
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United Kingdom Size 8–10 → us-4-5-58–10 to us-4-5-5
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United Kingdom Size 10.5–12.5 → us-4-5-510.5–12.5 to us-4-5-5
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United Kingdom Size 13–14.5 → us-4-5-513–14.5 to us-4-5-5
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United Kingdom Size 15–17.5 → us-4-5-515–17.5 to us-4-5-5
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