Knitting Needle Size Conversion Chart – AU, US & UK (mm)
Use this knitting needle size conversion chart to compare Australian metric (mm), US and traditional UK knitting needle sizes. Whether you're reading an older pattern or buying needles for a new project, the millimetre measurement is the most reliable way to find a match.
Australia generally uses metric knitting needle sizes. For example, 4.00 mm needles are commonly labelled US 6 or old UK 8. Modern UK needles often also display millimetres. Use the mm size if regional numbers differ.
Jump to conversion chart | Choosing needle sizes | FAQs
Knitting Needle Size Conversion Chart (Australia, US & UK)
In the table below, the AU / Metric (mm) column gives the actual needle diameter. The UK column uses older British/Canadian needle numbers, which may appear in vintage patterns.
| Australia (AU) / Metric | US Size | UK (Traditional) |
|---|---|---|
| 1.50 mm | 000 | — |
| 1.75 mm | 00 | — |
| 2.00 mm | 0 | 14 |
| 2.25 mm | 1 | 13 |
| 2.50 mm | — | — |
| 2.75 mm | 2 | 12 |
| 3.00 mm | — | 11 |
| 3.25 mm | 3 | 10 |
| 3.50 mm | 4 | — |
| 3.75 mm | 5 | 9 |
| 4.00 mm | 6 | 8 |
| 4.50 mm | 7 | 7 |
| 5.00 mm | 8 | 6 |
| 5.50 mm | 9 | 5 |
| 6.00 mm | 10 | 4 |
| 6.50 mm | 10½ | 3 |
| 7.00 mm | — | 2 |
| 7.50 mm | — | 1 |
| 8.00 mm | 11 | 0 |
| 9.00 mm | 13 | 00 |
| 10.00 mm | 15 | 000 |
| 12.75 mm | 17 | — |
| 15.00 mm | 19 | — |
| 19.00 mm | 35 | — |
| 25.00 mm | 50 | — |
What does — mean? A dash indicates there is no widely established direct equivalent in that numbering system. Don't guess a number: use the millimetre size specified in the pattern. Conversions are approximate and some manufacturers use slightly different numbers.
Are Australian and UK Knitting Needle Sizes the Same?
Not always. Australian needles are usually sold by diameter in millimetres, such as 3.25 mm, 4 mm or 5 mm. Modern UK needles are also commonly marked in millimetres, but older UK patterns may use a separate numbering system. In that traditional system, higher numbers indicate thinner needles (for example, old UK 10 corresponds approximately to 3.25 mm, while old UK 4 corresponds approximately to 6 mm).
How to Choose the Right Knitting Needle Size
- Check the pattern: Use its recommended needle diameter in mm whenever available.
- Read the yarn label: This gives a suggested needle size range, but it is a starting point rather than a guaranteed fit.
- Make a tension (gauge) swatch: Knit a small sample using the stated stitch pattern, wash or block it if the project calls for it, then count stitches and rows over the specified distance.
- Adjust if needed: Too many stitches in the measured width usually means you should try larger needles; too few suggests smaller needles.
- Consider the project: Lace, socks, ribbing and bulky garments may require different needle sizes even with similar yarn.
Common Needle Sizes and Yarn Weights
The following are broad starting ranges, not fixed rules. The knitting pattern and gauge should take priority.
| Yarn category | Typical needle range |
|---|---|
| Lace | 1.5–2.25 mm (often larger for open lace) |
| Super fine / fingering | 2.25–3.25 mm |
| Fine / sport | 3.25–3.75 mm |
| Light / DK | 3.75–4.5 mm |
| Medium / worsted | 4.5–5.5 mm |
| Bulky / chunky | 5.5–8 mm |
| Super bulky | 8–12.75 mm |
| Jumbo | 12.75 mm and above |
Knitting Needle Types: Does the Size Change?
Straight, circular and double-pointed needles can all use the same metric diameter. Their shape and length affect how you work, but a 4 mm straight needle and a 4 mm circular needle have the same nominal thickness. Check the shaft diameter, not the overall length, when matching a pattern.
How to Measure an Unlabelled Knitting Needle
Use a knitting needle gauge with labelled holes: slide the needle into the smallest opening it fits through comfortably. Alternatively, measure the smooth shaft with accurate callipers. Avoid measuring the tapered tip, which is narrower than the main shaft.
Knitting Needle Size FAQs
What is a 4 mm knitting needle in US and UK sizes?
It is commonly US size 6 or traditional UK size 8.
What is US size 8 in Australia?
US size 8 usually corresponds to 5.00 mm in Australia.
What is old UK size 10 in metric?
Old UK size 10 commonly corresponds to 3.25 mm.
Do Australian knitting needles use US numbering?
Usually not as their primary label. Australian needles and patterns generally use millimetres, although imported products may show both metric and US sizes.
Why are some conversion cells marked with a dash?
Not every metric diameter has an established regional number. A dash avoids suggesting an exact conversion where there isn't one.
Is the needle size on a yarn label always correct for my pattern?
No. It is a recommendation. The correct needle is the one that gives the specified gauge and the fabric your project requires.
Related Fosmore Guides
Reference basis: US-to-metric needle conversions and typical yarn-weight ranges follow Craft Yarn Council guidance; traditional UK numbers are approximate historical equivalents. This page does not require visitors to leave Fosmore to use the chart.
Disclaimer: Knitting needle sizes, historical numbering and yarn recommendations may differ between manufacturers and patterns. This guide is general information only. Verify the millimetre size and complete a gauge swatch before beginning a project, especially when following vintage or imported instructions.