Crochet hook size table
metric	british	alphabetical	numeric	bamboo	thickness
Germany	Canada, England	USA	USA	Japan	–
–	–	10 steel		–	1.0 mm
1.25 mm	16	8 steel	000	–	1.25 mm
1.5 mm	15	7 steel	00	–	1.5 mm
1.75 mm	14	5 steel	–	–	1.75 mm
2 mm	–	–	0	–	2.0 mm
–	–	–	–	0	2.1 mm
2.25 mm	13	B	1	–	2.25 mm
–	–	–	–	1	2.4 mm
2.5 mm	12	–	1 1/2	–	2.5 mm
–	–	–	–	2	2.7 mm
2.75 mm	–	C	2	–	2.75 mm
3 mm	11	–	2 1/2	3	3.0 mm
–	10	D	3	–	3.25 mm
–	–	–	–	4	3.3 mm
3.5 mm	–	E	4	–	3.5 mm
–	–	–	–	5	3.6 mm
–	9	F	5	–	3.75 mm
–	–	–	–	6	3.9 mm
4 mm	8	G	–	–	4.0 mm
–	–	–	–	7	4.2 mm
–	–	–	6	–	4.25 mm
4.5 mm	7	–	7	8	4.5 mm
–	–	–	–	9	4.8 mm
5 mm	6	H	8	–	5.0 mm
–	–	–	–	10	5.1 mm
–	–	–	–	11	5.4 mm
5.5 mm	5	I	9	–	5.5 mm
–	–	–	–	12	5.7 mm
6 mm	4	J	10	13	6.0 mm
–	–	–	–	14	6.3 mm
6.5 mm	3	K	10 1/2	–	6.5 mm
–	–	–	–	15	6.6 mm
7 mm	2	–	–	7 mm	7.0 mm
–	1	–	–	–	7.5 mm
8 mm	0	L	11	8 mm	8.0 mm
9 mm	00	M	13	9 mm	9.0 mm
10 mm	000	N	15	10 mm	10.0 mm
15 mm	–	P, Q	–	–	15.0 mm