Needle Sizes
Knitting Needle Size Conversion Chart
| Metric Size | US Size | UK Size |
| 2 mm | 0 | 14 |
| 2.25 mm | 1 | 13 |
| 2.5 mm | ||
| 2.75 mm | 2 | 12 |
| 3 mm | 11 | |
| 3.25 mm | 3 | 10 |
| 3.5 mm | 4 | |
| 3.75 mm | 5 | 9 |
| 4 mm | 6 | 8 |
| 4.5 mm | 7 | 7 |
| 5 mm | 8 | 6 |
| 5.5 mm | 9 | 5 |
| 6 mm | 10 | 4 |
| 6.5 mm | 10 ½ | 3 |
| 7 mm | 2 | |
| 7.5 mm | 1 | |
| 8 mm | 11 | 0 |
| 9.0 mm | 13 | 00 |
| 10 mm | 15 | 000 |
| 12 mm | 17 | |
| 15 mm | 19 | |
| 19 mm | 35 | |
| 25 mm | 50 |
Crochet Hook Size Conversion Chart - Standard
| Metric Size | US Size | UK Size | JPN Size |
| 2 mm | A-0 | 14 | 0 |
| 2.25 mm | B-1 | 12 | |
| 2.5 mm | 12 | 1 | |
| 2.75 mm | C-2 | 2 | |
| 3 mm | 11 | 3 | |
| 3.25 mm | D-3 | 10 | 4 |
| 3.5 mm | E-4 | 9 | 5 |
| 3.75 mm | F-5 | 6/7 | |
| 4 mm | G-6 | 8 | 7 |
| 4.5 mm | 7 | 7 | 8 |
| 5 mm | H-8 | 6 | 10 |
| 5.5 mm | I-9 | 5 | 11 |
| 6 mm | J-10 | 4 | 13 |
| 6.5 mm | K-10 ½ | 3 | 15 |
| 7 mm | 2 | ||
| 8 mm | L-11 | 0 | |
| 9 mm | M-13 | 00 | |
| 10 mm | N-15 | 000 |
approximate
Crochet Hook Size Conversion Chart - Steel
| Metric Size | US Size | UK Size | JPN Size |
| 0.5 mm | 14 | ||
| 0.6 mm | 12 | ||
| 0.75 mm | 14 | 10 | |
| 0.9 mm | 13 | 7 | 8 |
| 1.00 mm | 12 | 6 ½ | 6 |
| 1.25 mm | 10 | 5 ½ | 4 |
| 1.50 mm | 8 | 4 ½ | 2 |
| 1.75 mm | 6 | 3 ½ | 0 |
| 2 mm | 4 | 2 ½ | |
| 2.25 mm | 2 | 1 ½ | |
| 2.5 mm | |||
| 2.75 mm | 1 | 1 | |
| 3 mm | |||
| 3.25 mm | 0 | 0 | |
| 3.5 mm | 00 |
approximate