CrochetDubai

US to Japanese hook sizes

US crochet hook sizes converted to Japanese, with a link to the full detail page for every size.

Japanese sizes are not exact equivalents Japanese 号 (gō) hooks step in their own increments — 4/0号 is 2.5 mm, while the nearest US hook, C/2, is 2.75 mm. That quarter millimetre changes gauge in amigurumi. Where a Japanese pattern names a 号 size, buy the millimetre size, not the lettered equivalent.
USJapaneseDetail
140.6 mm
120.75 mm
100.9 mm
111 mm
71.25 mm
61.5 mm
51.75 mm
E/43.5 mm
G/64 mm
74.5 mm
H/85 mm
I/95.5 mm
J/106 mm
L/118 mm

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Last updated 2026-08-30.