Needle and hook size comparison chart
Knitting needles and crochet hooks are sized differently in different parts of the world, and even by different manufacturers. To make things even more confusing, there are different size ranges for the hooks used for thread crochet (steel hooks), to those used for yarn (aluminium, plastic, bamboo, wood etc.). The following is a guide to the equivalent sizes in the US, and the old 'imperial' sizes used in the UK, Canada and Australia, but you may come across other variations:
| knitting needles |
steel crochet hooks (for thread work) |
yarn crochet hooks |
| metric |
US |
|
|
|
Metric |
US (Boye) |
US (Clover) |
Imperial
(UK & Canada)
|
|
|
Metric |
US |
Imperial
(UK & Canada)
|
| 1.75mm |
|
15 |
|
|
0.4mm |
|
|
|
|
|
2.00mm |
0 |
14 |
| 2.00mm |
0 |
14 |
|
|
0.5mm |
|
14 |
|
|
|
2.25mm |
1/B |
13 |
| 2.25mm |
1 |
13 |
|
|
0.55mm |
|
|
|
|
|
2.50mm |
2 |
12 |
| 2.75mm |
2 |
12 |
|
|
0.6mm |
|
12 |
6 |
|
|
2.75mm |
2/C |
11 |
| 3.00mm |
-- |
11 |
|
|
0.65mm |
|
|
|
|
|
3.00mm |
3 |
11 |
| 3.25mm |
3 |
10 |
|
|
0.7mm |
|
|
|
|
|
3.25mm |
3/D |
10 |
| 3.50mm |
4 |
-- |
|
|
0.75mm |
14 |
10 |
5 |
|
|
3.50mm |
4/E |
9 |
| 3.75mm |
5 |
9 |
|
|
0.8mm |
|
|
|
|
|
3.75mm |
F |
|
| 4.00mm |
6 |
8 |
|
|
0.85mm |
13 |
|
|
|
|
4.00mm |
6 |
8 |
| 4.50mm |
7 |
7 |
|
|
0.9mm |
|
8 |
|
|
|
4.25mm |
G |
|
| 5.00mm |
8 |
6 |
|
|
1mm |
12 |
6 |
4 |
|
|
4.50mm |
7 |
7 |
| 5.50mm |
9 |
5 |
|
|
1.05mm |
|
|
|
|
|
5.00mm |
8/H |
6 |
| 6.00mm |
10 |
4 |
|
|
1.1mm |
11 |
|
|
|
|
5.50mm |
9 / I |
5 |
| 6.50mm |
10.5 |
3 |
|
|
1.2mm |
|
|
|
|
|
6.00mm |
10 / J |
4 |
| 7.00mm |
-- |
2 |
|
|
1.25mm |
|
4 |
3 |
|
|
6.50mm |
10 1/2 / K |
3 |
| 7.50mm |
-- |
1 |
|
|
1.3mm |
10 |
|
|
|
|
7.00mm |
- |
2 |
| 8.00mm |
11 |
0 |
|
|
1.4mm |
9 |
|
|
|
|
7.50mm |
|
|
| 9.00mm |
13 |
00 |
|
|
1.5mm |
8 |
2 |
2.5 |
|
|
8.00mm |
- |
0 |
| 10.00mm |
15 |
000 |
|
|
1.65mm |
7 |
|
|
|
|
9.00mm |
15 / N |
00 |
| 12mm |
17 |
-- |
|
|
1.75mm |
|
0 |
2 |
|
|
10.00mm |
P |
000 |
| 16mm |
19 |
-- |
|
|
1.8mm |
6 |
|
|
|
|
|
|
|
| 19mm |
35 |
-- |
|
|
1.9mm |
5 |
|
|
|
|
|
|
|
|
|
|
|
|
2mm |
4 |
|
1 or 14 |
|
|
|
|
|
|
|
|
|
|
2.1mm |
3 |
|
|
|
|
|
|
|
|
|
|
|
|
2.25mm |
|
|
0 |
|
|
|
|
|
|
|
|
|
|
2.5mm |
2 |
|
2/0 or 12 |
|
|
|
|
|
|
|
|
|
|
2.75mm |
1 |
|
|
|
|
|
|
|
The metric sizes are now shown in most modern patterns, but if you are using an old pattern and the hook size doesn't correspond to any of those in the table above, you will need to rely on that old faithful method of experimenting until you get the right tension. | 
) 
