Hook & Yarn Conversions
| Metric (mm) | Old UK Thread Size | Old UK Yarn Size | US Thread Size | US Yarn Size | Suggest UK Thread/Yarn | Suggested US Thread/Yarn | Suggested Australian Thread/Yarn |
| 0.60 | 7 | 14 steel | no.70 thread | ||||
| 0.75 | 6˝ | 13 steel | no.30-60 thread | ||||
| 0.85 | 6 | 12 steel | |||||
| 1.00 | 5˝ | 10 steel | no.20-30 thread | ||||
| 1.25 | 4˝ | no.10-20 thread | |||||
| 1.50 | 3˝ | 16 | 6 steel | no.10-20 thread | |||
| 1.75 | 2˝ | 15 | 5 steel | no.5 thread | |||
| 2.00 | 1˝ | 14 | B/1 | no.3 thread / 3-ply | |||
| 2.25 | 13 | 2 | |||||
| 2.50 | 2/0 | 12 | B/1 | 3-ply | |||
| 2.75 | 1 | ||||||
| 3.00 | 3/0 | 10 | C/2 | 4-ply | |||
| 3.25 | 0 | D/3 | |||||
| 3.50 | 9 | 00 | E/4 | 4-ply / double knit | |||
| 4.00 | 8 | F/5 | Double knit | Light Worsted | 8 ply | ||
| 4.25 | G/6 | ||||||
| 4.50 | 7 | 7 | Double knit / Aran | Light Worsted / Worsted | 8 ply/10 ply | ||
| 5.00 | 6 | H/8 | Aran | Worsted | |||
| 5.50 | 5 | I/9 | Aran | Worsted | |||
| 6.00 | 4 | J/10 | Aran / Chunky | ||||
| 7.00 | 2 | K/10˝ | Chunky | Bulky | 16 ply | ||
| 8.00 | L/11 | ||||||
| 9.00 | M/13 | ||||||
| 10.00 | N/15 | ||||||
| 11.00 | |||||||
| 12.00 | |||||||
| 13.00 | |||||||
| 14.00 | |||||||
| 15.00 | P/16 | ||||||
| 16.00 | Q | ||||||
| 17.00 | |||||||
| 18.00 | |||||||
| 19.00 | S | ||||||
| 20.00 |