Knitting needle sizes

A handy little guide to knitting needle sizes including size chart for US, European, and Japanese needles.

Are you looking for a chart that helps you convert metric sizes to US needle sizes? Or are you wondering why needle size matters and what is the best size for beginners? Then this page has all the answers for you. But first of all the most important part: The knitting needle size chart.

Metric sizeUS sizeUK size / Imperial
1 mm0000019
1.25 mm000018
1.5 mm00017
1.75 mm0015
2.0 mm014
2.25 mm113
2.5 mm(1.5)
3.0 mm(2.5)11
3.25 mm310
3.5 mm4
3.75 mm59
4.0 mm68
4.5 mm77
5.0 mm86
5.5 mm95
6.0 mm104
6.5 mm10 1/23
7.0 mm2
7.5 mm1
8.0 mm110
9.0 mm1300
9.5 mm14
10.0 mm15000
12.0 mm17
16.0 mm19
19.0 mm35
25.0 mm50

Now, how many sizes of knitting needles are there? As you can see, there are altogether 27 different sizes widely in use these days. But in this conversion chart, you might also see that some are not popular in certain countries. For example, European size 3 mm knitting needles convert to U.S. size 2.5. But this is a fractional size that has only been added by a selected few manufacturers in recent years. Traditionally most socks are being knitted with size 3 in America. This translated to 3.25 mm needles in the metric system.

So in some parts, this chart is only an approximation. Still, you can easily see that a 4 mm knitting needle converts to a U.S. size 6. And knitting needles sold as 5 mm in Europe can be found as size 8 on the other side of the Atlantic.

knitting needles in many different sizes on a table - close-up shot

Knitting needle sizes explained

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.

parts of a yarn label with weight and needle size
Close-up shot of a typical commercial yarn label

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:

  1. Your personal tension: Are you a tight or loose knitter? Your knitting style and even the needle material (wood vs metal) will have a huge influence on your gauge.
  2. The knitting stitch pattern: Typically, you will knit lace patterns using relatively large needles to create a lace like appearanges. Rib stitches, on the other hand, will benefit from using relatively small knitting needles.

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.

So, your first step should always, I repeat, always be knitting a gauge swatch to confirm you are knitting a satisfying fabric in line with your thoughts or the requirements of your pattern.

different knitting needle gauges on a table to find out what size a knitting needle has

what size knitting needles for beginners

As a beginner, needle size 8 to 9 (5 – 5.5 mm) and worsted weight yarn are an excellent starting point. Smaller needles will make it difficult to see the individual stitches, and quite fiddly to knit. The same can be said about too large needles. While they beckon beginners with the allure of finishing faster, they are typically quite unwieldy, heavy, and force you to learn awkward motions – especially if you have smaller hands.

Think of it as learning how to paint. You wouldn’t want to do it with a brush that is barely thicker than two hairs put together. At the same time, you wouldn’t want to use one where you need two hands to hold it either, eh? Now, I have a full guide to the best knitting needle for beginners here on my blog that covers other important aspects you might want to check out.

Needle size recommendation for different yarn weight:

Yarn weight #Common namesNeedle size
Lace #0Lace, Cobweb, Thread, Light fingering00-1
Superfine #1Baby, Fingering, Sock1-3
Fine #2Baby, Sport3-5
Light #3DK, Light, Worsted5-7
Medium #4Afghan, Aran, Worsted7-9
Bulky #5Bulky, Chunky, Craft, Rug9-11
Super Bulky #6Super bulky, Roving11+
Jumpy #7Jumbo, Roving17+

Again, please understand that these are only general recommendations. Two different companies might call their yarn DK weight but that doesn’t mean that both should be knitted with needle size 6 for the best results.

Does knitting needle length matter?

finding the right needle size and length for a cable project

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.

When you are knitting with single-pointed or double-pointed knitting needles, this is quite important. For the fingers of gloves, you might only need 10 cm (4 in) needles, while for socks, most knitters prefer 15 cm (6 in), and for a hat knit in the round you might need 20 cm (8 inches) to accommodate all stitches.

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

Explaining U.S. knitting needle sizes is a complicated topic and we have to delve a bit into history: With the popularization of knitting in the UK in the 18th century and the industrialization, the shift from handmade tools to mass-produced steel needles occurred. Needles were often also called wires because, by then, most dpns were indeed made out of durable steel wire. And thus they were measured in accordance with the standard wire gauge (SWG).

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.

historic gauge for knitting needle sizes as sold by Mrs Lambert in the 19th century
Source: Miss Lambert, My Knitting book; London, 1845, John Murray

(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.

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!

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.

On top of that, in the 1890ies the U.S. made the shift from being an importer of goods to an exporter. In the light of this newfound economic independence, US yarn manufacturers might have decided to come up with their own systemization, just like they came up with their own names for yarn weights (fingering weight is a good example). This might sound peculiar, but it really is quite the standard marketing trick to create customer loyalty.

Think of how Apple forced unique chargers and cables on their customers for two decades. Miss Lambert probably called her needle gauge “Standard Filière” for very similar reasons – distinction. The Singer Corporation famously heralded this change towards international marketing around that time with their sewing machines (source) with a kind of success that would dominate the industry for the whole century to come.

Susan Webster concludes in a noteworthy post that “then, somehow, magically, around the time of World War II, needle and gauge markers united around the “Standard American” size”. She argues that it could be a result of wartime restrictions. Decades of confusion among knitters might have elevated that demand.

These days, I see an increasing switch among U.S. pattern designers to the metric system for similar reasons. Since the Imperial and the U.S. knitting needle size system still exist side by side, recommending size 6 needles can be very confusing as knitters from both sides of the pond are likely to buy a given pattern.

Important: If you are following a history knitting pattern from the U.S. make very sure to research the needle size. Size 10 could be anything without context.

Anyway, that was my knitting needle size chart & everything you need to know about conversion to US sizes. Comment below in case you have any questions.

a knitting needle size chart with conversions between us size and mm and uk size

13 thoughts on “Knitting needle sizes”

  1. I really appreciate the information in this post. It’s so helpful for beginners like me. I’m going to start knitting soon and this information will be really helpful. Thanks!

    • i am not sure what you want to hear now? If you could be a little bit more specific, maybe I could help.
      I cannot, however, recommend patterns or yarn.

  2. Hi,
    Happy New Year to you.
    A complete newbie here, I will at some point attempt to tackle a cardi/kimono but it is a US pattern. It calls for US Size 17 12.0 mm, 24″ or 36″ Circular Knitting Needles and Lion Brand Wool Ease Thick & Quick Super Bulky Yarn (Pattern uses approximately 725).
    I have ordered 5 balls of Lion Brand Wool Ease Thick n Quick Super Chunky (ball weight 170g). My needles I have already are 12 mm but the yarn recommends 8 mm needles.
    Should I therefore use 8 mm needles? Apologies for being such a nim wit and thanks for your help.

    • Yes, you probably should use 8mm needles. A 50% difference is waaay too much in most cases. It will all depend a bit on your individual tension but that typically means you might have to use size 7mm or size 9mm needles.

  3. Hi Norman,

    It’s Poppy again, apologies but when the pattern states ‘ Cast On (31, 35) stitches’, does this mean I select 31 or 35 stitches? Sorry for being completely stupid!

    Thanks again in anticipation.

    King regards


  4. Hi, I have a 1970s Bernat afghan kit my late mother started but did not finish. So I would love to complete it, but the directions call for 1/2″ dia. “jackpins”. No needle conversion chart I found has helped me figure out the current equivalent. Can you help?

    • I can’t really help you with jackpins. However, since you have the yarn, you should be able to determine the yarn weight with the WIP (wraps per inch) method.
      THat should give you a good estimation which needle size you can use.
      And then I would use some spare yarn and knit a couple of swatches to compare your gauge with the fabric you have so far.
      Remember two things: A) you mother may or may not have used this exact needle size B) even if she did, she may have had a different gauge than you with the same needle size.
      So really, the instructions don’t matter at all, if you ask me.

    • I hope this helps you with your heirloom project. In the 1970s, there was a bit of a craze to knit with multiple strands on larger diameter knitting needles. The ones I have in my collection are approximately 1″ diameter. (We laughingly called them telephone poles.) Super bulky yarn and roving knitting in the 21st century have revived the larger diameter needles. You are probably going to find success with Boye size 19US/15 mm that can be found at Walmart. Before the larger diameter needles were manufactured, I believer people were knitting with novelty tools of their own devising from the hardware or craft departments (thus, jack pins). You may want to try making your own needles from a dowel rod.

  5. I am wanting to knit your basic scarf. How do I adapt the pattern, please, using size 8mm needles? How many stitches should I cast on? My wool is bulky, size 5. Thank you. Ann


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