Millimeters to old UK and Canadian sizes
Type a value in mm to get it in UK instantly.
4UK
That's 1.2× as thick as the needle for worsted yarn, while the needle for chunky yarn is 1.08× thicker.
Convert the other way: UK to mm
What it means
Which yarn suits that needle?
Typical needle sizes for each yarn weight; the ball band and your tension swatch have the final word.
The math
How to convert mm to UK
US and UK sizes are tables: US 6 = UK 8 = 4 mm, US 8 = UK 6 = 5 mm. Japanese size n is 2.1 + 0.3 × n mm.
Example: 6 mm = 4 UK.
Every unit
That needle in every system
Tables
mm to UK conversion table
| mm | UK |
|---|---|
| 2 mm | 14 UK |
| 2.25 mm | 13 UK |
| 2.75 mm | 12 UK |
| 3.25 mm | 10 UK |
| 3.5 mm | 9.5 UK |
| 3.75 mm | 9 UK |
| 4 mm | 8 UK |
| 4.5 mm | 7 UK |
| 5 mm | 6 UK |
| 5.5 mm | 5 UK |
| 6 mm | 4 UK |
| 6.5 mm | 3 UK |
| 8 mm | 0 UK |
UK to mm conversion table
| UK | mm |
|---|---|
| 0 UK | 8 mm |
| 3 UK | 6.5 mm |
| 4 UK | 6 mm |
| 5 UK | 5.5 mm |
| 6 UK | 5 mm |
| 7 UK | 4.5 mm |
| 8 UK | 4 mm |
| 9 UK | 3.75 mm |
| 9.5 UK | 3.5 mm |
| 10 UK | 3.25 mm |
| 12 UK | 2.75 mm |
| 13 UK | 2.25 mm |
| 14 UK | 2 mm |
Quick answers
Quick answers
- How many UK is 6 mm?
- 6 mm is 4 UK.
The units
About these units
Millimeters (mm)
The metric size: the needle’s diameter.
Old UK and Canadian sizes (UK)
Wire-gauge numbers that fall as the needle grows.
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