Needle Size Conversion
| Metric | Old UK | US Sizes (Approx.) |
| 2mm | 14 | - |
| 2.25mm | 13 | 1 |
| 2.5mm | 12 | - |
| 2.75mm | 12 | 2 |
| 3mm | 11 | 2.3 |
| 3.25mm | 10 | 3 |
| 3.5mm | 9 | 4 |
| 3.75mm | 9 | 5 |
| 4mm | 8 | 6 |
| 4.5mm | 7 | 7 |
| 5mm | 6 | 8 |
| 5.5mm | 5 | 9 |
| 6mm | 4 | 10 |
| 6.5mm | 3 | 10.5 |
| 7mm | 2 | - |
| 7.5mm | 1 | - |
| 8mm | 0 | 11 |
| 9mm | 0 | 13 |
| 10mm | 0 | 15 |
| 12mm | - | 17 |
| 15mm | - | 19 |
| 20mm | - | 36 |
Needle Length Conversion
| Length - Metric | Length - Imperial (Approx.) |
| 25cm | 10 inches |
| 30cm | 12 inches |
| 33cm | 13 inches |
| 35cm | 14 inches |
| 40cm | 16 inches |
| 60cm | 23.5 inches |
| 80cm | 31.5 inches |
| 100cm | 39.5 inches |