Knitting needle sizes can be confusing. That’s because different countries have different ways of numbering their knitting needles.
While the US and the UK use the same metric sizes, their numbering systems run in opposite directions.
In the US, needle sizes start at 0 and increase to 50. However, in the UK, sizes start at 14 and go up to 000.
In Japan, knitting needles use different standard metric sizes, starting at 2.1 mm and going up to 25 mm.
Confused yet?
To help you decipher the world of knitting needle sizes, refer to the charts below!
Knitting Needle Sizes Chart for US and UK
This knitting needle size conversion chart compares knitting needles in the US and UK, with crochet hook sizes thrown in for good measure!
| Metric (mm) | US Size | UK Size | Crochet |
|---|---|---|---|
| 2.0 mm | 0 | 14 | – |
| 2.25 mm | 1 | 13 | B |
| 2.5 mm | 1.5 | – | – |
| 2.75 mm | 2 | 12 | C |
| 3.0 mm | 2.5 | 11 | – |
| 3.25 mm | 3 | 10 | D |
| 3.5 mm | 4 | – | E |
| 3.75 mm | 5 | 9 | F |
| 4.0 mm | 6 | 8 | G |
| 4.5 mm | 7 | 7 | – |
| 5.0 mm | 8 | 6 | H |
| 5.5 mm | 9 | 5 | I |
| 6.0 mm | 10 | 4 | J |
| 6.5 mm | 10.5 | 3 | K |
| 7.0 mm | – | 2 | – |
| 7.5 mm | – | 1 | – |
| 8.0 mm | 11 | 0 | L |
| 9.0 mm | 13 | 00 | – |
| 10.0 mm | 15 | 000 | – |
| 12-12.75 mm | 17 | – | – |
| 15-16 mm | 19 | – | – |
| 19.0 mm | 35 | – | – |
| 20.0 mm | 36 | – | – |
| 25 mm | 50 | – | – |
Japanese Needle Size Chart
Note that Japanese needles have a different metric size than US and UK needles.
| Metric (mm) | JPN Size |
|---|---|
| 2.1 mm | 0 |
| 2.4 mm | 1 |
| 2.7 mm | 2 |
| 3.0 mm | 3 |
| 3.3 mm | 4 |
| 3.6 mm | 5 |
| 3.9 mm | 6 |
| 4.2 mm | 7 |
| 4.5 mm | 8 |
| 4.8 mm | 9 |
| 5.1 mm | 10 |
| 5.4 mm | 11 |
| 5.7 mm | 12 |
| 6 mm | 13 |
| 6.3 mm | 14 |
| 6.6 mm | 15 |
What is My Knitting Needle Size?
If you have knitting needles from all over the world or of unknown origins, your best bet for identifying their size is by using a knitting gauge.
A knitting gauge is a small tool made of plastic, metal or wood. Like a slice of Swiss cheese, it has a bunch of variously sized holes all over it.
Unlike Swiss cheese, these holes are precisely sized for measuring knitting needles!
This is how it works:
Take your mystery needle and poke it through a similarly-sized hole in the knitting gauge.
If the needle slides in smoothly and sits snugly in the hole, then you’ve just identified your needle size. Mystery solved!
A knitting gauge is super useful, and every knitter should have one in their toolbox.
Thankfully, there’s one to suit every knitter’s personality and needs, from animal lovers to those looking for plain utilitarian plastic. Below, some highly-rated favourites:
Knitting Needle Size Chart Printable
To make your knitting easier, I’ve made a printable of these charts, which you can download below.
Print it out, laminate it, and keep it handy for future questions on knitting needle sizes.
And there you are! May these two knitting needle size conversion tables help you on your knitting journey!
What if gage fits one way but not the other? It usually fits across but is bigger up and down.
I have minimal sight and miss knitting and crocheting very much, have been given 35 mm knitting needles, yes THIRTY FIVE MM I presume I can only make squares which is OK but have no idea of the yarn size I should use.
Help please
Wow! 35mm needles sound… enormous! I’d think big yarn meant for arm knitting might work?
My assorted crochet hooks have millimeters and also numbers 3,4 5, 6.
I have no A,B,C’s
Hi,
This might seem like a silly question but I haven’t found the definitive answer.
I am knitting with 5 mm needles and I read that in order to achieve greater stretch in a cast off I can increase the needle size twice. Does increasing the needle size twice mean going from 5 mm to 6 mm?
Or does it mean going from 5 mm to 7 mm?
Thanks in advance for your help.
Sorry for the late reply. This is a great question! Yes, it’s increasing the needle size is a great little hack for getting a stretchier cast off. I typically increase by 1mm (so from a 5mm to a 6mm) but going up to 1.5mm doesn’t hurt either.