Stitchbay guide
Knitting needle sizes: metric, US and old UK
Needles are sized by their diameter in millimetres. US sizes are numbers that go up with the needle (US 6 is 4 mm), and old UK sizes go the other way (UK 8 is 4 mm). When in doubt, use the millimetres.
| Metric (mm) | US | Old UK |
|---|---|---|
| 2 | 0 | 14 |
| 2.25 | 1 | 13 |
| 2.5 | – | – |
| 2.75 | 2 | 12 |
| 3 | – | 11 |
| 3.25 | 3 | 10 |
| 3.5 | 4 | – |
| 3.75 | 5 | 9 |
| 4 | 6 | 8 |
| 4.5 | 7 | 7 |
| 5 | 8 | 6 |
| 5.5 | 9 | 5 |
| 6 | 10 | 4 |
| 6.5 | 10½ | 3 |
| 7 | – | 2 |
| 7.5 | – | 1 |
| 8 | 11 | 0 |
| 9 | 13 | 00 |
| 10 | 15 | 000 |
| 12 | 17 | – |
| 15 | 19 | – |
| 19 | 35 | – |
| 25 | 50 | – |