Understanding knitting needle sizes can get extremely confusing even when you’ve been knitting for years, more so when you’re a newbie knitter. It’s hard to figure out what they mean, why they’re needed and how they might change the outcome of our latest knitting projects. So here’s our helpful mini-guide to knitting needle conversion, you can use as a reference tool for your work.
What Is Knitting Needle Conversion?
The differing range of knitting needle sizes allows you to work with a wider array of yarn and wool thicknesses, so it’s essential to note what size of needle you have available when browsing for a new yarn.
In the UK and wider Europe, the majority of knitting patterns utilise metric terminology when referring to knitting needles. All modern needles are currently sized in millimetres (mm), meaning that the greater the measurement, the thicker the needle’s overall width.
Conversion does not factor in the many styles of needles, including straight, circular and double-pointed.
What Are The Differences?
Vintage patterns are wildly different because knitting needles were once sized independently in the UK as well as in Canada. The sizes were the complete opposite of today’s knitting norms, as the greater the measurement, the thinner the width of the needle became.
A further complication is US needle sizing, to be aware of if you are purchasing yarn, patterns or needles from North America. Their conversion scale ascends from zero upwards, rather than working backwards from 000 (10mm) as we do.
How Do Needles Affect My Knitting?
Knitting needles can change the length of your stitches, the gauge of your knitting (how many stitches will fit onto one needle) varies depending on the size of your needles. Larger widths will ensure a larger gauge, although the body of the yarn itself makes a huge difference to the appearance of your project.
Conversion Chart
Use this chart for converting knitting needle sizes. You’ll find it especially helpful if you’re knitting from a vintage pattern or one of the many patterns from the USA.
| Metric | UK/EU | US |
| 2mm | 14 | 0 |
| 2.25mm | 13 | 1 |
| 2.5mm | ||
| 2.75mm | 12 | 2 |
| 3mm | 11 | |
| 3.25mm | 10 | 3 |
| 3.5mm | 4 | |
| 3.75mm | 9 | 5 |
| 4mm | 8 | 6 |
| 4.5mm | 7 | 7 |
| 5mm | 6 | 8 |
| 5.5mm | 5 | 9 |
| 6mm | 4 | 10 |
| 6.5mm | 3 | 10 ½ |
| 7mm | 2 | |
| 7.5mm | 1 | |
| 8mm | 0 | 11 |
| 9mm | 00 | 13 |
| 10mm | 000 | 15 |
| 12mm | 17 | |
| 15mm | 19 | |
| 20mm | 36 |
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