crochet hook size guide
Crochet Hook Size Guide Chart of Metric vs US / UK / Canada Crochet Hook Sizes*:

Millimeter Size (mm)
Crochet Hook Size (US)
Crochet Hook Size (UK/CA)
2.0 mm14
2.25 mmB-113
2.5 mm12
2.75 mmC-2
3.0 mm11
3.25 mmD-310
3.5 mmE-49
3.75 mmF-5
4.0 mmG-68
4.5 mm77
5.0 mmH-86
5.5 mmI-95
6.0 mmJ-104
6.5 mmK-10.53
7.0 mm2
7.5 mm1
8.0 mmL-110
9.0 mmM-1300
10.0 mmN-15000
12 mmO-16
15.0 mmP/Q-19
15.75 / 16.0 mmQ
17.5 mmR
19.0 mmS-35
25.0 mmU

*Trust the millimeter (mm) size as the letter / number can vary by manufacturer.