Needle size conversion chart
| Metric (mm) | US | UK / Canada | Typical yarn |
|---|---|---|---|
| 2 | 0 | 14 | Lace |
| 2.25 | 1 | 13 | Lace, Super fine |
| 2.5 | 1½ | – | Super fine |
| 2.75 | 2 | 12 | Super fine |
| 3 | 2½ | 11 | Super fine |
| 3.25 | 3 | 10 | Super fine, Fine |
| 3.5 | 4 | – | Fine |
| 3.75 | 5 | 9 | Fine, Light / DK |
| 4 | 6 | 8 | Light / DK |
| 4.5 | 7 | 7 | Light / DK, Medium / worsted |
| 5 | 8 | 6 | Medium / worsted |
| 5.5 | 9 | 5 | Medium / worsted, Bulky |
| 6 | 10 | 4 | Bulky |
| 6.5 | 10½ | 3 | Bulky |
| 7 | – | 2 | Bulky |
| 7.5 | – | 1 | Bulky |
| 8 | 11 | 0 | Bulky, Super bulky |
| 9 | 13 | 00 | Super bulky |
| 10 | 15 | 000 | Super bulky |
| 12.75 | 17 | – | Super bulky, Jumbo |
| 15 | 19 | – | Jumbo |
| 19 | 35 | – | Jumbo |
| 25 | 50 | – | Jumbo |
A dash means there is no standard size in that system. Yarn suggestions follow the Craft Yarn Council ranges; sizes at the edge of a range suit two weights.
Needle & hook size converterOpen the calculator
Reading needle sizes
- Metric is the diameter in millimetres. It is printed on most needles and is the most reliable way to compare brands.
- US sizes go up as needles get thicker: US 0 is 2 mm, US 8 is 5 mm, US 15 is 10 mm.
- Old UK and Canadian sizes go the other way: UK 14 is 2 mm and UK 0 is 8 mm. Vintage British patterns use these.
Choosing a needle size
Start with the size on your yarn label or pattern, then knit a gauge swatch. If you get too many stitches, go up a size; too few, go down a size.
Needle & hook size converterOpen the calculator
Questions
What is a US 7 in mm?
A US 7 needle is 4.5 mm (UK 7). It is used for DK and light worsted yarn.
What is 4 mm in US needle size?
4 mm is a US 6 (UK 8).
Are US sizes the same in Canada?
Modern Canadian needles usually show metric and US sizes. Older Canadian needles used the UK numbering.