Below is a helpful table to convert crochet hook sizes:
| Metric (mm) | Crochet hook |
|---|---|
| 2.00 mm | – |
| 2.25 mm | B |
| 2.50 mm | – |
| 2.75 mm | C |
| 3.00 mm | – |
| 3.25 mm | D |
| 3.50 mm | E |
| 3.75 mm | F |
| 4.00 mm | G |
| 4.50 mm | – |
| 5.00 mm | H |
| 5.50 mm | I |
| 6.00 mm | J |
| 6.50 mm | K |
| 7.00 mm | – |
| 7.50 mm | – |
| 8.00 mm | L |
| 9.00 mm | – |
| 10.00 mm | – |
| 12-12.75 mm | – |
| 15-16 mm | – |
| 19 mm | – |
| 20 mm | – |
| 25 mm | – |
Crochet Pattern Writing Tips from a Tech Editor
Tips for formatting your crochet hook conversions in your patterns:
- Use a consistent format to refer to crochet sizes throughout your pattern.
- The most popular format includes both Metric (mm) and Hook Sizes (letters) to cater to the vast majority of crocheters.
- In your introductory / set-up pages, include a section that lists all crochet hook sizes that will be used. You can also mention which parts of the pattern each hook is used for, such as ribbing.
- Make sure to include crochet sizes with your gauge / swatch tension.
- To really polish your pattern, watch out for inconsistent spacing!