Knitting needle conversion sizes chart

Knitting calculator conversion tools page

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EuropeanUSAJapanUK
1.5mm00 15
2mm0014
2.25mm10 or 113
2.5mm1.5112 or 13
2.75mm2212
3mm2.5311
3.25mm3410
3.5mm459 or 10
3.75mm559
4mm668
4.25mm6 or 777 or 8
4.5mm787
4.75mm7 or 896 or 7
5mm8106
5.5mm9115
5.75mm9 or 10124 or 5
6mm10134
6.25mm10 or 10.5143 or 4
6.5mm10.5153
7mm10.5 or 11Same as Euro from here2
7.5mm10.5 or 11 1
8mm11 0
9mm13 00
10mm15 000
12mm17 Same as Euro from here
12.75mm17  
15mm19  
19mm35  
20mm36  
25mm50  

Here’s a handy chart of knitting needle conversion sizes. It will help you convert American to UK to European mm to Japan size needles. Why does one knitting needle size go down and the others go up? Without the regular and easy communication we have between countries these days, manufacturing companies used to decide their own sizes. Slowly they formed into national standards for the whole country and then countries would work together to create standards for imports and exports. 

UK Needle Sizes

The British created their knitting needle sizes to match their metal wire gauge sizes. By this method, the number of the size goes up as the actual measured diameter gets smaller. Once more chunky and bulky weight yarns began to be mass produced in the late 20th Century, there was a need for super sized chunky knitting needles. When you’ve sized your needles down to size 000, it’s hard to know where to go after that. To resolve the issue, UK uses mm metric sizing the same as Europe and the other metric based countries upwards from the 12mm needle.

US Needle Sizes

As a contrast, US knitting needle sizes go up as the diameter of the needle gets bigger. However, it doesn’t match the metric width, nor does it match an imperial measurement either. Converting these sizes is not intuitive unfortunately, so it is useful to have the chart handy.

Japan Needle Sizes

Japan sizes for needles go up in size as the width of the knitting needle grows. Their work standard has historically been to knit extremely fine work up to a maximum circumference of 6.5mm. Knitting in bulky yarns is a very modern idea in Japan – really only the past few decades – so they do not try to convert these sizes. They simply use the metric mm knitting needle sizes the same as Europe, Scandinavia, Australia and New Zealand.

Other Considerations

When you are converting your knitting needle size from US to mm to UK to Japan, it is worth taking into consideration the yarn you are working with and the tension of your own personal knitting. This is why it is useful for knitters to grow a good size collection of needles with varying width, length and material (stainless steel, bone, wood etc). The pattern might ask you for a 4mm needle which converts to a US size 6, Japan size 6 or UK size 8. However, you may find after making your swatch, that you need to go up or down a needle size anyway.

Learning to vary your tension can be helpful though, most knitters like to be comfortable with their own method and style of knitting so, change the needle size instead.

UK sizes are not used so often now as modern knitting needles are generally sold in metric mm sizes. It’s still handy to have a conversion for these sizes handy in case you want to try a vintage pattern or you inherit a collection of older needles.

Have fun with your knitting and bookmark the tool pages that are most useful to you.

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