Knitting Needle Conversion & Crochet Hook Conversion Chart

Knitting needle sizes and crochet hook sizes are commonly given as either metric or US, and if you're fortunate, both. Same applies for knitting or crochet patterns. Sometimes, however, it's not so easy, and then I always refer to my dependable conversion chart. Very helpful for me, and I hope you find it useful too. If you prefer to have this as a PDF for future reference, then you can find that here.

I've also added a table below that converts inches to centimetres, again something that I'm always trying to figure out. I've rounded up, or down, the numbers to fit into the common knitting standards for most needle and cord lengths. 

 

 Metric  US Needle Sizes UK Old Needle Sizes (Imperial) US Hook Sizes UK Old Hook Sizes (Imperial)
2.00mm 0 14 -- 14
2.25mm 1 13 B/1 13
2.50mm 1 1/2 -- -- --
2.75mm 2 12 C/2 12
3.00mm 2 1/2 11 -- 11
3.25mm 3 10 D/3 10
3.50mm 4 -- E/4 --
3.75mm 5 9 F/5 9
4.00mm 6 8 G/6 8
4.50mm 7 7 US7 7
5.00mm 8 6 H/8 6
5.50mm 9 5 I/9 5
6.00mm 10 4 J/10 4
6.50mm 10 1/2 3 K/10 1/2 3
7.00mm 10 3/4 2 K/10 3/4 2
7.50mm -- 1 -- 1
8.00mm 11 0 L/11 0
9.00mm 13 00 M/13 00
10.00mm 15 000 N/15 000
11.50mm -- -- P/16 --
12.00mm 17 -- --
12.75mm -- -- US17 --
15.00mm 19 -- -- --
15.75mm -- -- Q --
16.00mm -- -- -- --
20.00mm 36 -- -- --
25.00mm 50 -- -- --

  

Inches
Centimetres
3.5"
9cm
5"
13cm
6"
15cm
9"
22cm
10"
25cm
12"
30cm
14"
35cm
16"
40cm
24"
60cm
32"
80cm
40"
100cm