US to Metric (mm) hook sizes
US crochet hook sizes converted to Metric (mm), with a link to the full detail page for every size.
| US | Metric (mm) | Detail |
|---|---|---|
| 14 | 0.6 mm | 0.6 mm |
| 12 | 0.75 mm | 0.75 mm |
| 10 | 0.9 mm | 0.9 mm |
| 11 | 1 mm | 1 mm |
| 7 | 1.25 mm | 1.25 mm |
| 6 | 1.5 mm | 1.5 mm |
| 5 | 1.75 mm | 1.75 mm |
| B/1 | 2.25 mm | 2.25 mm |
| C/2 | 2.75 mm | 2.75 mm |
| D/3 | 3.25 mm | 3.25 mm |
| E/4 | 3.5 mm | 3.5 mm |
| F/5 | 3.75 mm | 3.75 mm |
| G/6 | 4 mm | 4 mm |
| 7 | 4.5 mm | 4.5 mm |
| H/8 | 5 mm | 5 mm |
| I/9 | 5.5 mm | 5.5 mm |
| J/10 | 6 mm | 6 mm |
| K/10.5 | 6.5 mm | 6.5 mm |
| L/11 | 8 mm | 8 mm |
| M/13 | 9 mm | 9 mm |
| N/15 | 10 mm | 10 mm |
| P/Q | 15 mm | 15 mm |
| Q | 16 mm | 16 mm |
| S | 19 mm | 19 mm |
Other hook charts
Last updated 2026-08-30.