Crochet Yarn Overs and Yarn Unders: What’s the Difference?

Almost every crochet stitch includes the instruction “yarn over”. But what is a yarn over and how is it different from a yarn under? Does it really make a difference in your crochet?

Yes, it does make a difference. Let me explain. Read all the way to the bottom of the post, then watch the video.

I’m using American crochet terminology.

How to Yarn Over

Start with your hands in the ready position, as shown in the photos. The hook is in front of the working yarn.

Neutral "Ready" position for right hand
Neutral “ready” position for right hand

Your dominant hand holds the hook and your non-dominant hand controls the yarn, with the working yarn coming over your index finger. This means that if you are right-handed, the hook is in your right hand and the yarn in your left. If you are left-handed, the hook is in your left hand and the yarn is in your right.

Neutral "ready" position for left hand
Neutral “ready” position for left hand

Press back with the hook and at the same time bring the yarn over the hook from back to front. The yarn will be crossing the front of the hook from upper right to lower left if you are right-handed, and from upper left to lower right if you are left-handed.

Yarn over for right-handed crocheters
Yarn over for right-handed crocheters
Yarn over for left-handed crocheters
Yarn over for left-handed crocheters

How to Yarn Under

Start in the ready position as described above, but bring the hook over the top of the working yarn, so that the yarn crosses the front of the hook from lower right to upper left for right-handers, or from lower left to upper right for left-handers.

Yarn under for right-handed crocheters
Yarn under for right-handed crocheters
Yarn under for left-handed crocheters
Yarn under for left-handed crocheters

Single Crochet: Yarn Over and Yarn Under

To work a regular single crochet, insert the hook into the stitch, yarn over — notice the position of the yarn — and pull up a loop, then yarn over and pull through two loops on the hook.

Some crocheters work a yarn under instead of a yarn over at a crucial point. Often they don’t even know they are doing a yarn under! Here’s what typically happens:
Insert the hook into the stitch, yarn under — notice the position of the yarn — and pull up a loop, then yarn over and pull through two loops on the hook.

Why Does It Matter?

Take a look at the photo below. In the first few rows, I crocheted a regular single crochet, made with yarn overs. The two legs of these single crochet are parallel to one another.

regular sc compared to crossed sc
The stitch circled in red is crossed, while the stitch circled in green is straight.

Then I switched techniques on the last row. On that row, after I inserted the hook into the stitch, I did a yarn under then finished off the second step with a yarn over. In this example, the two legs of the single crochet are crossed.

The yarn unders create twisted stitches, but they also change the gauge and the drape of the fabric. Chances are, if you’ve been working unintended yarn unders, you’ve been having trouble matching the pattern gauge! Try it yourself and see the difference.

Some people like to use yarn under single crochet stitches for amigurumi projects. That’s fine, as long as it is intentional!

Double Crochet: Yarn Over and Yarn Under

Double crochet has three yarn overs, and thus three opportunities to make yarn unders. However, let’s concentrate on what happens when you do a yarn under right after you insert your hook into the fabric, as above.

Here’s a regular double crochet: Yarn over, insert the hook into the stitch, yarn over and pull up a loop, (yarn over, pull through 2 loops) two times.

See how the legs at the base of the double crochet are parallel?

double crochet with parallel legs made with yarn over
The strands on the base of this double crochet are parallel.

Here’s a twisted double crochet: Yarn over, insert the hook into the stitch, yarn under and pull up a loop, (yarn over, pull through 2 loops) two times.

Twisted double crochet stitches made with yarn under
The base of these double crochets are twisted.

This time, the legs at the base of the double crochet are twisted.

Know the Difference

If you are just learning to crochet, pay attention to the way you are wrapping the yarn over the hook. Get into the habit of checking that you are working a yarn over (unless the pattern says otherwise).

If you have been crocheting for a while and have only just discovered that you are doing unintentional yarn unders, it’s not too late to change!

Take time to study what you have been doing, then practice working yarn overs instead of yarn unders. It may feel strange at first, but you will eventually find that it is easier to get the yarn through the fabric with a yarn over.

Has this post been eye-opening to you? Have you discovered that you were yarn undering when you should have been yarn overing? Let me know in the comments.

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The yarn I’m using in the photos and video is Marly Bird’s Chic Sheep from Red Heart. The crochet hook is Clover Amour, size 5.5 mm.

Keep Learning

Want to know more about crochet? I’ve got resources and links to up your skill level.

7 thoughts on “Crochet Yarn Overs and Yarn Unders: What’s the Difference?”

  1. Edie, thank you for posting this explanation of yarn-overs and yarn-unders. I have run into this problem more times than I can remember in my crochet classes, and they can happen with both new and more experienced crocheters. Also, when yarn-unders become a habit, it is very difficult the make a change–even when the y-o is considerably easier to form. The difference in gauge between the two ways of forming a stitch is really drastic. However, you won’t believe how many times my effort to change the stitch formation being used has resulted in a “Well, so what? I don’t see the difference.” This explanation should be part of every basic crochet manual.

  2. I made exactly the same answer to you first question! Yes, it makes a difference! But not many people know they make it wrong. I saw it a lot in Germany, maybe because the hook is often hold as a knife and the thread is easier to catch with a yarn under.
    Don’t know why but I hate it , can’t bear it . There are even stitches that can’t be crocheted with yarn unders as the thread will drop from the hook… Reverse sc maybe (I don’t remember but I had the case in a class).
    Can’t remember of patterns with yarn under either.
    A yarn over should be a… yarn over

  3. I think we should always understand the mechanics of our stitches and the reasons for doing things a certain way. Then, if we wish, we can experiment, improvise and otherwise be the boss of our work and get the results we seek.
    I can imagine that doing yarn unders might be desirable in some situations, wanting a denser fabric, for instance.
    Knowledge is empowering. Thanks for this post.

  4. I’ve been crocheting for 10 years and never realized that I’ve been doing yarn unders this whole time. Honestly I’m a little embarrassed. 🙁

  5. Hello, Edie. I have all your books on crocheting and I feel like I know you!
    A question: why does almost everyone in the US go from dc to tc without using the 1/2 tc? The half treble (US) is a beautiful stitch, and it is exactly the right height to fill that gap between double and treble!
    Let’s hear it for the half treble and maybe you can do a book about it! (And I would love to be a test crocheter for you anytime!)
    Best to you and thank you in advance. jeannie

  6. That’s a good questions, and I don’t really have an answer. I did just design a sweater in all-over half double, which is one of my favorite stitches. However, now that you. mention it, I’ll have to go try more with half treble. Or–did you mean half treble (UK), which is half double (US)? Isn’t that the challenge with terminology?

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