REFERENCE CHART
Crochet hook size chart: letters and millimeters
US crochet hooks are named with a letter, a number, or both. The letter and number can vary a little between brands, but the millimeter size can’t, so always match the mm in your pattern.
Crochet hook size chart
| Metric | US size |
|---|---|
| 2.25 mm | B-1 |
| 2.75 mm | C-2 |
| 3.25 mm | D-3 |
| 3.5 mm | E-4 |
| 3.75 mm | F-5 |
| 4 mm | G-6 |
| 4.5 mm | 7 |
| 5 mm | H-8 |
| 5.5 mm | I-9 |
| 6 mm | J-10 |
| 6.5 mm | K-10.5 |
| 8 mm | L-11 |
| 9 mm | M/N-13 |
| 10 mm | N/P-15 |
| 11.5 mm | P-16 |
| 15 mm | P/Q |
| 16 mm | Q |
| 19 mm | S |
| 25 mm | T/U/X |
These are the hook sizes CozyKnit offers for crochet projects.
Which hook for which yarn?
As a rough guide from the Craft Yarn Council’s standards:
- Fingering and sock yarn: 2.25–3.5 mm (B-1 to E-4)
- Sport yarn: 3.5–4.5 mm (E-4 to 7)
- DK yarn: 4.5–5.5 mm (7 to I-9)
- Worsted and aran yarn: 5.5–6.5 mm (I-9 to K-10.5)
- Bulky yarn: 6.5–9 mm (K-10.5 to M/N-13)
The full ranges, including lace and super bulky, are in the yarn weight chart.
Steel hooks are numbered differently
Small steel hooks for crochet thread use their own numbers, and a bigger steel hook number means a smaller hook. Go by the millimeter size if your pattern lists one.
When your gauge is off
Too many stitches in your swatch means your fabric is tighter than the pattern’s, so try a bigger hook. Too few stitches means try a smaller hook.