Modern needles usually carry a millimetre diameter. Use that physical measurement as the anchor when translating a pattern written with US or older UK sizing.
Enter the physical diameter. Exact common matches appear in the result; the complete reference remains below.
Legacy UK: 000 · 10 mm
| Millimetres | US label | Legacy UK |
|---|---|---|
| 2 mm | 0 | 14 |
| 2.25 mm | 1 | 13 |
| 2.75 mm | 2 | 12 |
| 3.25 mm | 3 | 10 |
| 3.5 mm | 4 | — |
| 3.75 mm | 5 | 9 |
| 4 mm | 6 | 8 |
| 4.5 mm | 7 | 7 |
| 5 mm | 8 | 6 |
| 5.5 mm | 9 | 5 |
| 6 mm | 10 | 4 |
| 6.5 mm | 10½ | 3 |
| 8 mm | 11 | 0 |
| 9 mm | 13 | 00 |
| 10 mm | 15 | 000 |
A 4 mm needle is commonly US 6 and legacy UK 8.
Three labels can describe one needle
Metric sizing states diameter in millimetres. US sizing uses a rising number sequence, while legacy UK sizing generally runs in the opposite direction. A bare “size 8” is therefore ambiguous unless the pattern’s system is known.
StitchMeasure shows the systems side by side without treating a regional number as a physical measurement. This is particularly useful for inherited patterns and unmarked tools.
When the marking is missing
Measure the straight shaft with a physical needle gauge, not the tapered tip. Once the diameter is known, use the regional label only to interpret the pattern, then swatch to confirm the finished fabric.
How to use this page
- Select a millimetre diameter.
- Compare the common US and legacy UK labels.
- Check the needle itself or a sizing gauge if the marking is worn.
What to check before you rely on the result
- Legacy UK numbering runs in the opposite direction from millimetres.
- Mappings can vary at less-common sizes.
Source note
This original presentation was checked against the relevant Craft Yarn Council reference. Regional labels may vary; no third-party graphic or table layout is reproduced.
Consulted authority ↗