This blog post is all about knitting needle sizes and conversion charts. Why is this so important to know? For circular knitting needles, the distinction is mainly a matter of preference. The longer the needle body, the more you can use the needles as leverage but the heavier they are. And of course, whenever you are knitting in the round, the stiff length of the needle itself defines the minimum diameter you can knit with these comfortably – except you are using the magic loop technique (e.g. you cannot knit a 10-inch circle with needles that are 4 in long each). How are knitting needles sized – a short history A handy little guide to knitting needle sizes including size chart for US, European, and Japanese needles. I tend to use metric sizes as no matter where you are 2.0mm is still 2.0mm, and here in Australia most of the patterns you buy will list both the metric size and the equivalent United Kingdom and/or Canadian size. Of course, new materials (like celluloid) might also explain the departure from the SWG (as they required different machines and thus resulted in different sized needles). One also has to keep in mind that around 1910, commercial flights across the Atlantic were not available, and neither were telephone calls possible. Unlike today, knitters around the world were much less connected internationally and the world moved much slower and still a bit in isolation.

Given the many immigrants (but also the rising economic power) from Germany, this mixture cannot be seen as all that surprising from a certain point of view – especially as it feels a little bit more intuitive that a larger number constitutes a larger size. It would be very limited to assume the U.S. only imported haberdashery from the UK. After all, companies like addi have been selling fine knitting needles since 1829!Unlike Swiss cheese, these holes are precisely sized for measuring knitting needles! This is a standard plastic gauge for measuring knitting needle sizes. If you need to work out what size you should use for to knit a particular item, I recommend that you knit yourself a tension square or two. Knitting needle sizes can be confusing. That’s because different countries have different ways of numbering their knitting needles. So according to the yarn comparison chart a pattern using a US 9 will be used to knit a worsted or heavy weight yarn and a Canadian/Uk 9 is more likely to be used to knit with a finer yarn (probably a fingering). 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.

On top of that, different materials (e.g. wool, alpaca, or cotton) are also an important factor. Some of these might change their appearance drastically after the first wash.

Japanese Needle Size Chart

Side note: The SWG was only implemented in 1884. Before that, it was the Birmingham Wire Gauge; keep that in mind when you follow historic patterns). That, of course, does not explain the conundrum of the US needle sizes. Why don’t they follow the Imperial system? To be quite honest, nobody really knows! It remains a fact, however, that from around 1900 US manufacturers started selling their own needle gauges – following no system at all. Or rather, the actual sizes followed (more or less) the Imperial system but the numbers were rising, much like the metric system popular in mainland Europe. If the needle slides in smoothly and sits snugly in the hole, then you’ve just identified your needle size. Mystery solved!

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. If you look at Miss Lambert’s “ My knitting book” from 1845, you will find her marketing a “ Standard Filière” that bears a strong resemblance to the wire gauges used in the British industry at that time and follow the same systemization. Other authors, such as Hope, Mee, and Gaugain also advertised their own needle gauges. And this explains why the smallest knitting needles have the largest numbers in the UK. Source: Miss Lambert, My Knitting book; London, 1845, John Murray A pattern typically only provides you with a size, aka the diameter of the needle. The rest is up to your own preference. Your knitting needles need to be long enough to accommodate all stitches without them being squeezed together so tightly that they fall off whenever you relax. The yarn label of the most commercially produced yarns should provide you with a size range. It has to be noted that these kinds of recommendations are only a first step. The right needle size for you will largely depend on two factors:Now, you might be wondering about the difference between knitting needle sizes? Why are there so many and which size should you use? What’s the difference? Well, depending on your yarn weight, you will need a different needle with a different diameter to create an attractive fabric! This can be an incredibly complicated topic or super simple. So, let’s go through the details step-by-step. Close-up shot of a typical commercial yarn label