Crochet hook size chart
US hook letters and numbers and the matching metric size.
| Metric | US size |
|---|---|
| 2.25 mm | B-1 |
| 2.5 mm | – |
| 2.75 mm | C-2 |
| 3.125 mm | D |
| 3.25 mm | D-3 |
| 3.5 mm | E-4 |
| 3.75 mm | F-5 |
| 4 mm | G-6 |
| 4.25 mm | G |
| 4.5 mm | 7 |
| 5 mm | H-8 |
| 5.25 mm | I |
| 5.5 mm | I-9 |
| 5.75 mm | J |
| 6 mm | J-10 |
| 6.5 mm | K-10½ |
| 7 mm | – |
| 8 mm | L-11 |
| 9 mm | M/N-13 |
| 10 mm | N/P-15 |
| 11.5 mm | P-16 |
| 12 mm | – |
| 15 mm | P/Q |
| 15.75 mm | Q |
| 16 mm | Q |
| 19 mm | S |
| 25 mm | T/U/X |
| 30 mm | T/X |
Source: Craft Yarn Council’s www.YarnStandards.com. Letter and number sizes vary by brand – always go by the millimetre size printed on the package.
Frequently asked questions
What size is an H crochet hook in mm?
An H-8 hook is 5 mm.
What hook do I use for worsted yarn?
The standard range for medium (4) yarn is 5.5–6.5 mm (I-9 to K-10½); many patterns use 5 mm (H-8).
Size charts
- Knitting needle size chart
- Knitting needle to crochet hook sizes
- Yarn weight chart
- Baby and child size chart
- Adult sweater size chart
- Hat, mitten and sock size chart
- Wraps per inch (WPI) chart
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