When you’re new to a craft like knitting, learning about the tools of the craft is crucial! Let’s learn about needles, and answer some common questions. Use the list below to jump to each topic.
- What are knitting needles?
- Understanding knitting needle sizes and lengths
- But SERIOUSLY… why do I need so many knitting needles for a single project?
- Notions
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What are knitting needles?
Knitting needles are the tools used by hand-knitters to make fabric, one stitch at a time. They’re basically sticks with pointy ends. When knitting, you have a row of loops on one of these sticks, it’s held in your left hand. Your right hand holds the other needle, and you use the two needle tips together to form new loops on the right-hand needle tip. Stitch by stitch, the row gradually transfers over to that right-hand needle. The two hands and two needle tips work together. So you always need a PAIR of needles, you can’t knit with just one.

To knit, you’ll need some knitting needles! This post covers all the different kinds; straight needles, circular needles, and double pointed needles (DPNs). Each type of knitting needle comes in a range of sizes (size means the diameter), various lengths (length means how long the needle is from tip to tip), and different materials too.
Why are there so many different KINDS of knitting needles?
Because there are different shapes of fabric to be knit (think blankets vs. the teeny-tiny tube that forms the thumb of a mitten), different needle types are required.
Three kinds of knitting needles
Straight needles
These are the classic needles you imagine, they’ve been around for ages. They have stoppers on the end, so your stitches don’t fall off that end, and come in pairs, because you need two needles to knit! Using straight knitting needles you can knit back and forth in rows to create flat pieces of fabric.
Straight needles may be made of bamboo, plastic, different metals, or hardwood in a range of different sizes (that means diameter) and lengths.

But, to be completely honest, I’m a knitting pattern designer, and I don’t think I even own any straight needles. I can’t remember the last time I knit on straight needles. That’s because anything you can make on a pair of straight needles, you can also knit on circular needles. That said, I think that the speed-knitters of the world use straight needles, and if you love your straight needles, you do you – keep on clicking away!

Circular needles
A circular needle consists of a pair of needles connected by a bendy cord. You can use circular needles to knit back and forth in rows (just like you can with a pair of straight needles), but you can also use them to knit around and around in ’rounds’ to form a seamless tube. With a long circular needle, you can knit the tiniest of tubes by using the Magic Loop technique, or with a pair of circular needles you can utilize its sibling, the Two Circular technique – both of these methods are alternatives to working on DPNs (double pointed needles).

You work using both needle tips, so if you’re working a piece back and forth in rows, there’s no danger that your stitches will drop off the other end of the bendy needle.
The tips of circular needles may be made of bamboo, hardwood, different sorts of metal, or plastic. The cord of circular needles is often made of plastic, or less commonly of metal. Circular needles come in different sizes (that means the diameter of the tips), and in a range of lengths (circular needles are measured from needle tip to needle tip).
The basic kind of circular needles are called ‘fixed circular needles’. This means that the cord is permanently attached to the needle tips… they never come apart (unless they break).

There is, however, another kind of circular needle; interchangeable needles. Generally purchased in a set, interchangeable circular needles have needle tips in a range of sizes (that means the diameter), and cords in a range of lengths, so you may have a single set of 5mm / US#8 tips, but by changing out the cord, can make it into a 24″, 32″, 40″, 47″, or 60″ long circular needle. These interchangeable needles provide a lot of flexibility in a single package.

One limitation to a circular needle is that you cannot knit a tube that’s much smaller, in circumference, than the length of the needle itself (measured from needle tip to needle tip). Although shorter needles do exist, the smallest circular needles that I feel comfortable using is 16″ long. So when working a smaller tube, like a mitten, sock, or small sweater sleeve, you must use another method. You can either use a much longer circular needle (32″+ works best for me) and the Magic Loop method, or you can use double-pointed needles (DPNs).


DPNs : Double pointed needles
Double pointed needles (often called DPNs) are are used for knitting in rounds to form seamless tubes. They can be used for very small numbers of stitches; like at the top of a hat, mitten thumbs, or socks, as well as for larger diameter pieces like sweater yokes and bodies. Because double pointed needles stick out either end of their ‘set of stitches’, there is no minimum number of stitches that they can hold.
DPNs come in sets of 4 or 5 needles, and may be made of bamboo, hardwood, metal, plastic, or even carbon-fibre. They come in different sizes (that means the diameter of the tips), and in a few lengths (measured from tip to tip). Shorter DPNs (6″ / 15cm) are used for socks, mittens and the crown decreases of a hat. Longer DPNs (8″ / 20cm) would be used for larger diameter tubes like sweaters, hats or cowls.
Learn how to cast on to double pointed needles, how to knit in the round on double pointed needles, and how to switch to double pointed needles at the top of a hat.
The difference between ‘size’ and ‘length’ when we’re talking knitting needles
When we describe knitting needles, there are two measurements that matter; size and length. The first one, size, actually means the diameter of the needle. Depending on where you live, you probably recognize needle sizes described by either diameter measured in millimetres, OR you use the US knitting needle size number range. My trusty needle gauge from the 90’s includes both. Check out our knitting needle size conversion table <add anchor link>.
To use a needle gauge to measure your needle size, find the smallest hole that your needle tip fits through; that is the size you have!
The second measurement is length. Length means how long the needle is, and length is measured from tip to tip (for circular needles and DPNs) or tip to end (for straight needles). Length matters because you need enough length on the needle or the cord to hold all of the stitches in a given row or round.
But why are there so many different sizes of knitting needles?
Because yarn comes in many different weights (that is, how skinny or thick the strand itself is), and the finished fabric that knitters want to create varies (from very firm or dense, to very loose and gauzy), needles also come in a wide array of sizes. Knitting with teeny tiny needles forms teeny tiny loops (stitches), using fine and skinny yarns. Knitting on larger needles, you form bigger loops (stitches), using heavier (thicker) yarns. So each of the needle types comes in a range of sizes (diameters) from the tiniest ‘pins’ to the super thick like tree-trunks.
Needle Size really means Needle Diameter
When a pattern calls for a 5mm (US#8) needle, this means the diameter of the needle tip. When a pattern tells you to use or switch to ‘larger needles’ or ‘smaller needles’ this means the larger diameter, or smaller diameter needles; it doesn’t mean anything about which length of needle you’ll use.
Knitting Needle Size Conversion Table
Needle Sizes (Diameter) in Metric & US# Sizes | ||
---|---|---|
Metric size (diameter) | US Size # | |
1.5 mm | US#000 | |
1.75 mm | US#00 | |
2 mm | US#0 | |
2.25 mm | US#1 | |
2.5 mm | ||
2.75 mm | US#2 | |
3 mm | ||
3.125 mm | US#3 | |
3.25 mm | US#3 | |
3.5 mm | US#4 | |
3.75 mm | US#5 | |
4 mm | US#6 | |
4.5 mm | US#7 | |
5 mm | US#8 | |
5.5 mm | US#9 | |
6 mm | US#10 | |
6.5 mm | US#10 1/2 | |
8 mm | US#11 | |
9 mm | US#13 | |
10 mm | US#15 | |
12.5 mm | US#17 | |
15 mm | US#19 | |
19 mm | US#35 | |
25 mm | US#50 | |
35 mm | US#70 |
My most commonly used needles are in the range of 3.25mm (US#3) through 5.5mm (US#9), because I tend to knit a lot of hats, mittens, sweaters, and blankets and prefer sport, DK, worsted, and aran weight yarns. But I’ve collected a LOT of needles over the years…
Measure Knitting Needles from tip to tip (or tip to end)
When a pattern calls for a specific length of needle, it’s measured from tip to tip. Or for straight needles, which only have 1 tip, it’s measured from tip to end.
Length matters because as you’re knitting the fabric, all of the stitches in a single row or round must fit on the needle(s). For a 8″ wide scarf, a 12″ long pair of straight needles will be suitable. But for a 36″ wide blanket, all those stitches simply won’t fit on a 12″ long needle… I’d work this size of a piece on a longer circular needle, like 32″ or 40″ long.
When knitting in the round, you can begin a top-down sweater on a 16″ long circular needle (because there aren’t too many stitches at a neckline)… but as you increase and increase through the yoke of the sweater, you’ll need to switch to a longer circular needle, because at some point all the additional stitches will no longer fit on that 40cm / 16″ long needle.
Knitting Needle Length Conversion Table
There are a few common lengths for knitting needles; here is how they convert from metric (cm) to imperial (inches).
Needle Lengths in Metric (cm) & Imperial (inches) | ||
---|---|---|
Metric (cm) | Imperial (inches) | Usage Notes |
15cm | 6″ | DPN length, for socks, mittens, top of hats |
20cm | 8″ | DPN length for larger tubes. Straight needle length for scarves or small pieces |
23cm | 9″ | (Uncommon) Tiny circular needle length; for socks, mittens, baby/child sleeves |
25cm | 10″ | (Uncommon) Tiny circular needle length for sleeves. Straight needle length for scarves or small pieces |
30cm | 12″ | (Uncommon) Tiny circular needle length; for sleeves. Straight needle length for larger pieces |
40cm | 16″ | Circular needle length for hat brims (baby through adult), sweater necklines, sleeves for larger adult sizes |
50cm | 20″ | Circular needle length for adult hat brims, sweater necklines, baby sweater yokes and bodies |
60cm | 24″ | Circular needle length for sweater necklines, cowls, and you can sometimes get a hat brim to stretch around a 24″ needle too in my experience! It’s also good for baby and child sweater bodies. |
80cm | 32″ | Circular needle length for anything you might imagine: sweater bodies, blankets, shawls, and it’s long enough to use for the Magic Loop technique too |
100cm | 40″ | Circular needle length for anything you might imagine: sweater bodies, blankets, shawls, Magic Loop technique |
120cm | 47″ | Circular needle length for blankets, larger sweaters and Magic Loop technique |
150cm | 60″ | Circular needle length for BIG projects like blankets, massive shawls |
What do ‘larger needles’ and ‘smaller needles’ mean in a pattern?
First of all, ‘larger‘ and ‘smaller‘ in this context refer to size, which means needle diameter rather than length. Patterns almost never specify precisely the needle size you should use to knit them. They usually say ‘suggested needles’, and give a needle size to start swatching with. Because the gauge (that is, the size of stitches) you will get when knitting with a 5mm needle is different than the gauge I will get, you may need to use a 4.5mm or 5.5mm needle in order to get gauge. Patterns often give gauge as, for example, 18 sts & 26 rows in stockinette using larger needles. Then they suggest a smaller needle that is, for example, 2 sizes smaller, and instruct you to use ‘smaller needles’ when knitting the neckline or cuff ribbing. If you used a 4mm to get gauge, select a needle that’s about 1-3 sizes smaller (say, 3.25mm, 3.5mm, or 3.75mm) as your ‘smaller needle’ for working the parts of the pattern that call for a ‘smaller’ needle.
The pattern will say switch to smaller needles, and that means switch to the same needle type, but in the smaller diameter. It doesn’t say anything about what length to use, because it’s knowledge you’re expected to have or to figure out; that is, if you’re knitting a neckline, you’ll use a fixed 16 or 20″ circular needle, or DPNs, or a long circular with magic loop.
How do I know when to switch length?
For this question I have the somewhat unsatisfying answer: whenever suits you. Some knitters like it squishy, with lots of stitches on their needles so they are ‘spring loaded’ and ready to go. Other knitters prefer their stitches more spread out, so there is no change they will pop off the end as they knit. You want to change to a longer needle when the stitches become TOO squishy for your liking. You want to switch to a shorter needle when the stitches become TOO spread out for your liking.
If you’re starting a project and you aren’t sure if your needles will be too short or too long…just give it a go! The worst that can happen is that the stitches aren’t perfectly comfortable on your needles, OR that you need to head back to the yarn shop for another pair. I like to see if I can make it work with what I have first.
How can I tell which knitting needle size I need?
But SERIOUSLY… why do I need so many knitting needles for a single project?
Each project needs slightly different types of needles, because the shape of fabric and size of fabric you’re creating varies. Think about the difference between a large rectangle of knit fabric for a blanket, versus the tiny little tubes you knit when you’re making the thumb of a mitten, or a sock. A sweater is made up of several different sized tubes; a body tube, two sleeve tubes, and a yoke tube, which decreases in size to the size of one’s neckline. Also, ribbing requires a different gauge (and thus needle size) than stockinette stitch does; so in addition to different tube sizes, you will often need different needle sizes (diameters) too.
Crochet hooks, darning needles, and other NOTIONS
Notions is a catch-all term for “all the other stuff you’ll need” to make a knitting project. Here are a few…
While you only need yarn and needles to get started, you’ll soon discover the use for several other tools. A needle gauge will help you identify the size (diameter) of needles that aren’t labelled. To weave in yarn ends, you’ll need a yarn or darning needle. To keep track of where you are, you’ll use stitch markers. When you place stitches on hold, you may use stitch holders, or just a scrap of waste yarn. Scissors are helpful. A cable needle is used when knitting cable stitch patterns. A soft tape measure is useful for measuring how far you have knit, or measuring your body when you’re choosing which size to knit. Crochet hooks can help when you drop a stitch. A pom pom maker makes creating basic pom poms or out-of-this-world pompoms a breeze! And you might even end up with some other interesting tools like a Tunisian crochet hook!
Start with SIMPLE (our most popular free patterns!)
The Simple Collection contains a baker’s dozen fabulous free patterns. And just like the rest of Tin Can Knits patterns, these free patterns professionally produced, tech edited, and sized inclusively from baby-to-big. Are you ready to learn to knit and purl with the simple Wheat scarf? Take the next step with the Barley hat? Try your first sweater following Flax? Learn to knit socks (quick!) with Rye or Rye Light? Each of these excellent designs is supported by an in-depth tutorial to guide you as you learn, stitch by stitch.
New tutorials, right to your inbox!
We’ll write you a note a couple times a month to share our new knitting tutorials, patterns and stories!
New Knitters, Begin Here! | Tin Can Knits
February 24, 2022 @ 6:00 am
[…] Needles […]
February 8, 2022 @ 10:16 am
Hi! I’m looking at the Rye socks pattern and it call for DPN 3.25 and 3.75, but I find only 3, 3.5 and 4 mm here. Should I substitute up or down?
February 10, 2022 @ 1:59 pm
Hi – I think you’ll be best off with 3.5 and 4mm needles for the Rye socks.
September 3, 2021 @ 4:51 pm
Hi, Can you tell me where you got the image of the circular knitting needles with the flat ends. I have been looking everywhere for a seller.
September 6, 2021 @ 7:01 am
Hi, I’m not sure what you mean about circular knitting needles with ‘flat ends’. I think there are knit picks interchangeable needles and Addi fixed circular needles shown, if that helps.
February 18, 2021 @ 6:28 pm
Allo. I would like very much to have the totorial for the cardigan, thank you .
February 18, 2021 @ 10:21 pm
Hi Marie – You can find all of our project tutorials here: https://tincanknits.com/support/category/project-tutorials
Let’s Knit a Hat | Tin Can Knits
August 18, 2020 @ 3:13 pm
[…] Needles: You will need 3 types of needles for this hat. Circular needles in 2 sizes as well as double pointed needles in the larger size. Why all the needles you ask? The smaller circular needle (US 6 / 4mm) is for the ribbing, which you want to be a little tighter. The larger circular needle (US 8 / 5mm) is for the body of the hat. The Double Pointed Needles (DPNs) are for the decreases in the hat. If you don’t want to use DPNs you can also try the Magic Loop Method with a long circular. For more information on knitting needles check out our needle post here. […]
Let’s make a Beloved Bonnet | Tin Can Knits
March 31, 2020 @ 10:54 pm
[…] You can find the pattern on our website or Ravelry. The pattern lists the supplies you need; yarn, needles, stitch markers, and what gauge to achieve, but to be honest, matching gauge precisely isn’t […]
Let’s knit a scarf | Tin Can Knits
October 22, 2019 @ 3:33 pm
[…] and 5mm circular needles (if you don’t know a thing about yarn check out this post, or needles check out this post). There are many yarns and needles that will work for your first scarf so we recommend a trip to […]
March 2, 2016 @ 9:54 am
I’m an intermediate knitter, but I’ve never done a swatch for gauge. do you have a tutorial or other information anywhere that teaches that?
March 2, 2016 @ 9:04 pm
Yep! You can check out our gauge tutorial here.
January 18, 2016 @ 3:06 pm
I am looking at the Simple collection- and trying to not buy a ton of needles–but I think I still need different lengths- is it possible to get around this, or…?
January 18, 2016 @ 9:47 pm
It will depend on what you are knitting. For the Wheat the length doesn’t much matter, for a blanket you will need a 24″ or longer, hats generally take 2 sizes of needles because you want a nice tight rib at the start. The needles recommended are ones you would use often for hats though, a good investment in my opinion. For the cowl you will need a 16″ for the short and a 32″ for the long (no way around it). Socks you can use double points or a long circular (you can try a 32″ but I find a 40″ needle suits me better). For the sweater you will need all the recommended needles.
July 30, 2013 @ 12:41 am
Apart from yarn, needles are my next big love. I am always buying more it would seem. :-)