Techniques

Needle & Hook Sizes

US, metric, and UK sizes side by side. A dash means there’s no matching size in that system. When in doubt, go by the metric size, which is the true diameter.

Knitting Needles

US	Metric	UK
8/0	0.5 mm	24
6/0	0.75 mm	22
5/0	1 mm	19
4/0	1.25 mm	18
000	1.5 mm	17
–	–	16
00	1.75 mm	15
0	2 mm	14
1	2.25 mm	13
2	2.75 mm	12
–	3 mm	11
3	3.25 mm	10
4	3.5 mm	–
5	3.75 mm	9
6	4 mm	8
7	4.5 mm	7
8	5 mm	6
9	5.5 mm	5
10	6 mm	4
10.5	6.5 mm	3
–	7 mm	2
–	7.5 mm	1
11	8 mm	0
13	9 mm	00
15	10 mm	000
17	12 mm	–
19	15 mm	–
35	19 mm	–
50	25 mm	–

Crochet Hooks (Yarn)

Metric	US Letter
2.25 mm	B-1
2.75 mm	C-2
3.25 mm	D-3
3.5 mm	E-4
3.75 mm	F-5
4 mm	G-6
4.5 mm	7
5 mm	H-8
5.5 mm	I-9
6 mm	J-10
6.5 mm	K-10.5
8 mm	L-11
9 mm	M-13
10 mm	N-15
12 mm	P-16

Steel Hooks (Thread)

US	Metric
00	3.5 mm
0	3.25 mm
1	2.75 mm
2	2.25 mm
3	2.1 mm
4	2 mm
5	1.9 mm
6	1.8 mm
7	1.65 mm
8	1.5 mm
9	1.4 mm
10	1.3 mm
11	1.1 mm
12	1 mm
13	0.85 mm
14	0.75 mm