10 mm knitting needle size
A 10 mm knitting needle is US size 15 and UK size 000. Millimetres are the definitive measure — match the mm if your pattern uses another system.
Millimetres are the reliable measure — US numbers/letters and the old UK scale are conventions. When in doubt, match the mm. “—” means no standard equivalent in that system.
US, UK & metric sizing — why they differ
Knitting needles and crochet hooks are sold by millimetre (the actual diameter), but US patterns use numbers/letters and old UK patterns use a reversed numbered scale (bigger number = thinner). Always trust the mm. Pairs with our yarn weight converter to pick the right tool for your yarn.
Knitting needle size chart (mm · US · UK)
| mm | US | UK |
|---|---|---|
| 2 | 0 | 14 |
| 2.25 | 1 | 13 |
| 2.75 | 2 | 12 |
| 3 | — | 11 |
| 3.25 | 3 | 10 |
| 3.5 | 4 | — |
| 3.75 | 5 | 9 |
| 4 | 6 | 8 |
| 4.5 | 7 | 7 |
| 5 | 8 | 6 |
| 5.5 | 9 | 5 |
| 6 | 10 | 4 |
| 6.5 | 10.5 | 3 |
| 7 | — | 2 |
| 7.5 | — | 1 |
| 8 | 11 | 0 |
| 9 | 13 | 00 |
| 10 | 15 | 000 |
| 12 | 17 | — |
| 15 | 19 | — |
| 19 | 35 | — |
| 20 | 36 | — |
| 25 | 50 | — |
Crochet hook size chart (mm · US)
| mm | US |
|---|---|
| 2.25 | B-1 |
| 2.75 | C-2 |
| 3.25 | D-3 |
| 3.5 | E-4 |
| 3.75 | F-5 |
| 4 | G-6 |
| 4.5 | 7 |
| 5 | H-8 |
| 5.5 | I-9 |
| 6 | J-10 |
| 6.5 | K-10.5 |
| 8 | L-11 |
| 9 | M/N-13 |
| 10 | N/P-15 |
| 11.5 | P-16 |
| 15 | P/Q |
| 16 | Q |
| 19 | S |
FAQ
A US 8 needle is 5.0 mm (UK 6). The most common beginner size, US 6 / 4.0 mm / UK 8, suits worsted-weight yarn.
An H-8 crochet hook is 5.0 mm — the most popular hook, ideal for worsted-weight yarn. I-9 is 5.5 mm and J-10 is 6.0 mm.
The old UK/Imperial scale runs backwards: 14 is tiny (2 mm) and 000 is large (10 mm). It's a historical wire-gauge system, which is why metric mm is now standard worldwide.