US numbers to millimeters
Type a value in US to get it in mm instantly.
4mm
That's 1.07× as thick as the hook for sport yarn, while the hook for DK yarn is 1.13× thicker.
Convert the other way: mm to US
What it means
Which yarn suits that hook?
Steel hooks for thread use a separate, reversed numbering and are not covered here. Brands differ slightly above 6 mm.
The math
How to convert US to mm
Hook sizes are a table: H-8 = 5 mm, G-6 = 4 mm, J-10 = 6 mm. The letter and the number name the same hook.
Example: 6 US = 4 mm.
Every unit
That hook in every system
Tables
US to mm conversion table
| US | mm |
|---|---|
| 1 US | 2.25 mm |
| 2 US | 2.75 mm |
| 3 US | 3.25 mm |
| 4 US | 3.5 mm |
| 5 US | 3.75 mm |
| 6 US | 4 mm |
| 7 US | 4.5 mm |
| 8 US | 5 mm |
| 9 US | 5.5 mm |
| 10 US | 6 mm |
| 10.5 US | 6.5 mm |
| 11 US | 8 mm |
| 13 US | 9 mm |
| 15 US | 10 mm |
mm to US conversion table
| mm | US |
|---|---|
| 2.25 mm | 1 US |
| 2.75 mm | 2 US |
| 3.25 mm | 3 US |
| 3.5 mm | 4 US |
| 3.75 mm | 5 US |
| 4 mm | 6 US |
| 4.5 mm | 7 US |
| 5 mm | 8 US |
| 5.5 mm | 9 US |
| 6 mm | 10 US |
| 6.5 mm | 10.5 US |
| 8 mm | 11 US |
| 9 mm | 13 US |
| 10 mm | 15 US |
Quick answers
Quick answers
- How many mm is 1 US?
- 1 US is 2.25 mm.
- How many mm is 10 US?
- 10 US is 6 mm.
- How many mm is 6 US?
- 6 US is 4 mm.
The units
About these units
US numbers (US)
The number after the letter, from 1 to 15.
Millimeters (mm)
The diameter of the shaft.
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