Needle and hook sizes

Pick a size to see it in mm, US and UK.

Knitting needles
mm	US	UK
1.5	000	No number
1.75	00	No number
2	0	14
2.25	1	13
2.75	2	12
3	No number	11
3.125	3	No number
3.25	3	10
3.5	4	No number
3.75	5	9
4	6	8
4.25	6	No number
4.5	7	7
5	8	6
5.25	9	No number
5.5	9	5
5.75	10	No number
6	10	4
6.5	10 ½	3
7	No number	2
8	11	0
9	13	No number
10	15	No number
12.5	17	No number
12.75	17	No number
15	19	No number
19	35	No number
25	50	No number
35	70	No number

Crochet hooks
mm	US
2.25	B-1
2.5	No number
2.75	C-2
3.125	D
3.25	D-3
3.5	E-4
3.75	F-5
4	G-6
4.25	G
4.5	7
5	H-8
5.25	I
5.5	I-9
5.75	J
6	J-10
6.5	K-10 ½
7	No number
8	L-11
9	M/N-13
10	N/P-15
11.5	P-16
12	No number
15	P/Q
15.75	Q
16	Q
19	S
25	T/U/X
30	T/X

The Craft Yarn Council table gives no UK hook numbers.

Go by the millimeters: numbers vary between brands. A dash means no number for that size.

Sources

mm and US numbers: Craft Yarn Council, Hooks & Needles, read 12 November 2026.
UK needle numbers: KnitPro, Knitting Needle Sizes & Conversion Guide, kept only where Wikipedia (Knitting needle) gives the same number. Both read 12 November 2026. Left empty: 9 and 10 mm (the two disagree), 1.5 and 1.75 mm (not in KnitPro).

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