Here’s Everything You Need to Know About Circular Knitting Needles

Circular Knitting Needles

The circular knitting needle may seem like a specialty tool, but it could actually be the most useful needle in your knitting bag.

Sure, circular needles — two tapered needles connected by a flexible cord — are great for larger projects and knitting seamlessly in the round. But they’re so much more than that — you can use them instead of straight needles in any project, and you can also use them instead of double-point needles with the help of magic loop.

Before you go trading in all your needles for circulars, it’s important to understand cord lengths. The needle tips themselves follow the same rules as straight needles, but circulars come in a variety of cord lengths, too.

So, say a pattern calls for size 7 16″ needles: That first number refers to the needle size (aka the size of the needle head), and the second one is the length of the needles from tip to tip.

Most patterns will tell you which cord length you need for your project, but if your’e going rogue, here’s our handy guide to cord lengths.

The Key to Cord Lengths

three circular knitting needles


Good for: really, really narrow projects, like baby hats, and sleeves

This the shortest length you’ll find — anything with a smaller circumference will need to be worked on double-points, because it just isn’t possible for the needles on a shorter cord to even come together to work stitches.


Good for: small projects, knitting in the round

These needles are perfect when the project is just a bit too large to fit on double-pointed needles, including hats (for grown-ups and for kids), baby-sized sweaters and booties, and collars and sleeves on the sweaters you knit for grown-ups. Hat patterns will often ask you to use a 16″ circular needle to work the brim, and then switch you over to double-pointed needles as the hat gets smaller at the crown.


Good for: most projects, especially sweaters


Good for: medium-sized projects knitted flat or in the round

The 29″ needle can be used for things like baby blankets or cardigans that are large but not as big (or heavy) as a shawl or adult-sized blanket.

If you’re knitting a sweater in the round, this is a solid choice for working the body.


Good for: heavy or large projects that will be knitted flat; small circumference projects knit with magic loop

Knitting something heavy like a shawl on straight needles can be a pain in the wrist — literally! That’s when you break out the 36″ circular needles. They put all the weight of the project onto the cord, allowing you to speed along as you knit, while the rest of the knitting is on your lap or on the table. Straight needles also have a limited amount of space on them, so casting on 340 stitches is probably impossible. Again, not so for 36″ circular knitting needles.

This is also a great length if you want to try knitting a sleeve with the magic loop method instead of DPNs.

40″ and Up

Good for: knitting socks and sleeves two at a time, bed-size blankets

Circular needles also come in lengths of 40″ and 47″, and even go longer than that.

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27 Responses to “Here’s Everything You Need to Know About Circular Knitting Needles”

  1. Pat Gruber

    Please, if your project calls for a 3mm but you only have a 5mm same length, still co same amount of stitches? Ty

  2. Jacqueline

    I have an interest in knitting and i just started but with straight needles. I’m in Kenya and iv really struggled getting the Circular needles especially for knitting baby blanket. Kindly assist me on how to purchase. Thank you.

  3. Pat shaw

    I have got 16inch 4mm circular needels the baby hat pattern says 71 sts there is not enough sts for the needles do i nned a smaller size.

    • scott biales

      You are fine. It will be a bit hard for the first row or two then gets easer as the hat will stretch enough.

  4. Jeanne

    My beanie pattern calls for US 17, 20” cord. But, I can’t find a 20”cord. I bought a US 17, 24” cord, but I feel like it’s too long. Any tips?


    Good summary, but I’m surprised you don’t mention interchangeable cable needles. I don’t use anything else these days, unless absolutely necessary. (I’ve collected a lot of straight needles over my life, but since the last couple of moves, I only have a vague idea of where they are, and I always have a project on at least one pair of needles.) Also, with end pieces, the cable becomes an instant stitch holder, with no transfer needed.

    • Laura

      Is it possible to put this in a graph or print this out so it’s in my with my knitting stuff?

    • Pat shaw

      I have got 16inch 4 mm circular kneedles baby hat pattern says cast on 71 sts there is not enough sts for the kneedles do i need smaller ones.

  6. Dianne

    Socks are knit very easily on 9” circular needles, only using dpn for the toe. It’s been a game changer for me!

  7. Eldora Upton

    I love to crochet, but now that we have an Online Shopping Mall I don’t have much time for myself. I like to knit too, but crocheting is my favorite.

  8. Anna

    I knit a lot of socks and use the smallest size I can, but have to revert to 4 needles for toes casting off. Not used magic loop before.

  9. Janise Fournier

    Is it a good idea to store circular needles wound up? I have made a container whereby they are all ‘flat’. They are very annoying when they want to curl while one is knitting. I then have to swirl them in hot water to straighten them; doesn’t happen with a suitable container.

    • Susan K Miner

      So what is a suitable container for circular needles? I use them almost exclusively anymore.

    • Donna Vassar

      No longer have any straight needles (except a couple pairs small double point for specific small projects),

      • Pamela McCamant

        I use two 16” when I’m decreasing for a crown on a hat rather than double points.
        I have trouble with losing needles or worse stitches sliding off.
        I also use my 9” to hold stitches when making cables.

        You forgot about 12” circulars.

        • Elizabeth Bell

          What a good idea. I can never use double pointed needles when finishing the crown of a hat as I keep dropping stitches.