3.5 mm knitting needle
3.5 mm
US 4 · UK — · Sport
What this size is for
Present in the American scale and absent from the British one, which steps from 3.25 to 3.75.
In each scale
| Diameter | 3.5 mm |
| US size | 4 |
| UK / Canadian size | — |
| Yarn weight | Sport |
Nearby sizes
| mm | US | UK | Yarn |
|---|---|---|---|
| 2.75 | 2 | 12 | Fingering, 4-ply |
| 3 | 2/3 | 11 | Fingering |
| 3.25 | 3 | 10 | Fingering to sport |
| 3.5 | 4 | — | Sport |
| 3.75 | 5 | 9 | Sport to DK |
| 4 | 6 | 8 | DK |
| 4.5 | 7 | 7 | DK to worsted |
Frequently asked questions
What is a 3.5 mm knitting needle in US and UK sizes?
US 4 and UK —. The millimetre figure is the actual diameter and the only one that means the same thing everywhere.
Does this size exist in both scales?
Not in the British scale, which does not extend this far. The American number is 4.
What yarn suits a 3.5 mm needle?
Sport. Present in the American scale and absent from the British one, which steps from 3.25 to 3.75.
Why do the two scales run in opposite directions?
The British scale counts down from the thickest wire in a gauge, in the same way a wire gauge does — more drawing operations, higher number, thinner. The American scale simply counts up from the finest needle. Neither is wrong; they were never designed to be compared, and the only size where the numbers coincide is 4.5 mm, which is size 7 in both.