Needle & Hook Size Converter
Needle and hook sizing really shouldn’t require this much Googling. Choose whether you’re working with knitting needles or crochet hooks, enter the size you have, and convert it between metric, US and UK/Canadian sizing.
Prefer a good old-fashioned chart? You’ll find the full conversion tables below too.
Needle & Hook Size Converter
Choose whether you're converting knitting needles or crochet hooks, select the sizing system you have, then pick your size.
Good to know
Needle and hook numbering systems are not perfectly standardised, especially with older UK/Canadian and some crochet hook sizes. Metric millimetres are the most reliable reference, so when in doubt, go by the mm size shown on your pattern or tool.
Knitting Needle Conversion Chart
Compare metric, US and older UK/Canadian knitting needle sizes. Where there isn't a recognised standard equivalent, you'll see a dash.
| Metric | US | UK / Canadian |
|---|---|---|
| 2.0 mm | 0 | 14 |
| 2.25 mm | 1 | 13 |
| 2.5 mm | 1½ | 12 |
| 2.75 mm | 2 | 12 |
| 3.0 mm | 2½ | 11 |
| 3.25 mm | 3 | 10 |
| 3.5 mm | 4 | — |
| 3.75 mm | 5 | 9 |
| 4.0 mm | 6 | 8 |
| 4.5 mm | 7 | 7 |
| 5.0 mm | 8 | 6 |
| 5.5 mm | 9 | 5 |
| 6.0 mm | 10 | 4 |
| 6.5 mm | 10½ | 3 |
| 7.0 mm | 10¾ | 2 |
| 7.5 mm | — | 1 |
| 8.0 mm | 11 | 0 |
| 9.0 mm | 13 | 00 |
| 10.0 mm | 15 | 000 |
| 12.0 mm | 17 | — |
| 15.0 mm | 19 | — |
| 19.0 mm | 35 | — |
| 25.0 mm | 50 | — |
Crochet Hook Conversion Chart
Crochet hook sizing varies a little more between manufacturers, so metric millimetres are always the safest reference.
| Metric | US | UK / Canadian |
|---|---|---|
| 2.0 mm | B-1 | 14 |
| 2.25 mm | B-1 | 13 |
| 2.5 mm | C-2 | 12 |
| 2.75 mm | C-2 | 12 |
| 3.0 mm | D-3 | 11 |
| 3.25 mm | D-3 | 10 |
| 3.5 mm | E-4 | 9 |
| 3.75 mm | F-5 | 9 |
| 4.0 mm | G-6 | 8 |
| 4.5 mm | 7 | 7 |
| 5.0 mm | H-8 | 6 |
| 5.5 mm | I-9 | 5 |
| 6.0 mm | J-10 | 4 |
| 6.5 mm | K-10½ | 3 |
| 7.0 mm | — | 2 |
| 8.0 mm | L-11 | 0 |
| 9.0 mm | M/N-13 | 00 |
| 10.0 mm | N/P-15 | 000 |
| 12.0 mm | O | — |
| 15.0 mm | P/Q | — |
| 16.0 mm | Q | — |
| 19.0 mm | S | — |
| 25.0 mm | U | — |
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