Knitting Needle Size Chart

US, UK/Canadian, and metric needle sizes don't line up in any obvious way — this table converts between all three so you can follow a pattern written in a different system than the needles in your bag.

Metric (mm)	US Size	UK / Canadian Size
2.0 mm	0	14
2.25 mm	1	13
2.75 mm	2	12
3.0 mm	—	11
3.25 mm	3	10
3.5 mm	4	—
3.75 mm	5	9
4.0 mm	6	8
4.5 mm	7	7
5.0 mm	8	6
5.5 mm	9	5
6.0 mm	10	4
6.5 mm	10.5	3
7.0 mm	—	2
7.5 mm	—	1
8.0 mm	11	0
9.0 mm	13	00
10.0 mm	15	000
12.0 mm	17	—
16.0 mm	19	—
19.0 mm	35	—
25.0 mm	50	—

UK/Canadian sizing runs in the opposite direction from US sizing — a larger UK number means a thinner needle. When in doubt, go by the metric millimeter measurement; it's the one constant across every system.