How to knit the i-cord cast-on

A step-by-step tutorial on knitting the i-cord cast-on and important tips and tricks

Your project starts with an i-cord cast-on and you have no clue how to knit it? Then this tutorial will show two very easy ways to start your knitting with a well-rounded edge.

someone holding up a swatch with an icord cast-on in blue yarn

The i-cord was named by Elizabeth Zimmermann because it was so easy that even an idiot could knit it. Yet by abbreviating it, she removed the negative connotation and turned it into something that could also be very smart (i-ntelligent). Basically, it’s a very truncated form of knitting a super small diameter project in the round on straight needles.

As it’s so easy, it quickly became very popular and people like Stephen West started to incorporate it in (almost) every design to create a very well-rounded edge on all sides. Some prefer to knit the actual i-cord first and then pick up stitches but you can also knit the i-cord edge in one breath. I’m going to show you both versions.

Let’s dive right into it!

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Instructions: How to knit the i-cord cast-on

someone knitting an icord cast-on with blue yarn

The easiest and stretchiest way to knit an i-cord cast-on works in two steps. First, you knit an actual i-cord, and then you pick up stitches from the edge!

Active Time 5 minutes
Total Time 5 minutes


  1. Cast on three stitches with a longtail cast-on using needles that are one size bigger than the ones you want to knit your project with.

    casting on three stitches the normal way to start the icord cast-on
  2. Slide the stitches back to the other end and start knitting an i-cord that is three stitches wide.

    starting to knit an icord
  3. Continue knitting the i-cord until you've knitted as many rows as you want your project to be wide.

    continuing knitting the icord until its long enough as the project should be wide
  4. Then, slide the three stitches back to the right end of your needle, switch to the smaller needles, and knit a k3tog centered.

    starting the row by knitting a centered double decrease
  5. From here, pick up one stitch from the first knit V of the i-cord - either with your knitting needles or using a crochet hook. Go underneath both legs of the stitch and slip the resulting loop back to your right needle.

    picking up a stitch through the first knit v of the icord
  6. Continue picking up one stitch from every knit V of the i-cord. Make sure that you keep the i-cord pinned between your fingers and that it doesn't twist around. You have to pick up stitches from one continuous line of knit stitches.

    continuing picking up one stitch for every stitch of the icord
  7. Make sure that you also pick up a stitch through the very first row of the icord. It can sometimes be a little bit slanting towards the bottom/hidden. Otherwise, you don't end up with a nice edge.

    pickng up one last stitch through the very last stitch of the icord
  8. Turn your work around and continue knitting according to your knitting stitch pattern.

    knit across the return row according to your pattern


Instead of knitting the actual i-cord with one needle size bigger, you can also use the same size and then skip every third or fourth stitch as you pick up stitches. Essentially the row gauge of your i-cord and the stitch gauge of your knitting stitch pattern need to meet.

If you plan a larger project, I definitely recommend knitting a swatch. It's very easy for the fabric to flare out after the i-cord cast-on because it was too tight (see below for more details).

Reading tip: How to knit the i-cord bind off

An alternative way to knit the i-cord cast-on

Some people just don’t like picking up stitches. It certainly makes the process a bit cumbersome and it takes quite a while. As an alternative, you can also knit the i-cord cast-on in a continuous way. It comes, however, with its own problems. Still, here’s how to knit that:

Step 1: Cast on three stitches any way you like.

starting the icord cast-on by casting on three stitches the normal way

Step 2: Slip all three stitches back to the left needle (purlwise – so point to point).

having slipped back three stitches to the left needle

Step 3: Knit a kfb into the first stitch.

starting the icord cast-on with a kfb

Step 4: Knit across the remaining two stitches (you should have four stitches on your needles at the end of this first row).

knitting across the remaining stitches

Step 5: Slip back three stitches to the left needle. One remains on the right needle.

slipping back three stitches to the left needle

Step 6: Knit another kfb into the first stitch.

start the row with a kfb

Step 7: Knit across the remaining two stitches (5 stitches on the needle).

knit across the remaining stitches again

Step 8: Continue repeating steps 5-7 until you’ve cast on the required number of stitches.

continue repeating these steps to knit your icord cast-on

Step 9: Slip back three stitches one more time and knit these three stitches together (k3tog).

From here, you can simply turn your work around and continue knitting according to your pattern.

close up of the alternative icord cast on in green yarn

The problem with this method is, however, that you typically end up with one row of very elongated stitches. That’s because you tend to stretch out the KFB stitches as you knit across and it typically doesn’t look very pretty.

Also, as the actual i-cord ends up a bit tighter than the rest of the fabric, you often end up with flare compared to the first method I showed you.

comparing two versions of the icord cast-on side by side
The two versions side by side. See how the blue version is quite a bit neater without flaring out?

Important tips and tricks

As I said in the introduction, an i-cord is basically nothing else but knitting three or four stitches in the round. Because the gap is so short, you get away with doing it on straight needles. The vital part here is that you are knitting stockinette stitch.

Why vital? Because stockinette stitch does not have a square gauge. Typically you need something like 10 stitches and 14 rows to knit a square. As a result, you have to adjust the way you knit the i-cord cast-on if you don’t want your fabric to pucker or flare.

That’s why I recommend using the first method I showed you because then you can easily skip stitches as you pick up according to the gauge of the knitting stitch pattern.

For a larger project, this essentially means: you need to knit a swatch in stockinette stitch and find out your row gauge (so the gauge of your i-cord). And then, you need to knit another swatch using the knitting stitch pattern for the body of your project and find out the stitch gauge (here’s my tutorial on how to find out your gauge).

a big knitted gauge swatch and someone counting stitches

And then, essentially you have to make these two gauges meet. This can be either done by using a bigger or smaller needle for either part or by skipping stitches as you pick up stitches from the i-cord. But here’s the easiest way:

  1. Measure out 10 stitches in one horizontal row of your swatch for the body of your project. (e.g. 10 stitches are 4.7 centimeters)
  2. Check how many rows you need to cover the same distance on your stockinette stitch swatch going up vertically. (e.g. 4.7 centimeters take 14 rows.)
  3. And then, you simply have to pick up 10 stitches evenly for every 14 rows of the i-cord. Easy as that!

Sounds a bit too complicated? Well, as a rule of thumb, I would typically skip every third stitch if for stockinette stitch. This, of course, also means you have to knit your i-cord quite a bit longer (1/3 longer to be quite precise).

Anyway, that’s how to knit the i-cord cast-on. Comment below in case you need any further help.

how to knit the icord cast on - step by step for beginners

1 thought on “How to knit the i-cord cast-on”

  1. Dear Norman. Please allow me to make a correction. You wrote: “The i-cord was named by Elizabeth Zimmerman because she thought it was so easy that even an idiot could knit it.” This is not accurate. “Idiot Cord” was around when EZ was a girl, and she learned it with one of those spools with pegs at the top – around which you wound wool until eventually cord emerged from the opening. As an adult, EZ figured out how to make Idiot Cord on knitting needles, but she thought the name was quite rude, so she changed it from Idiot Cord to I-Cord.
    Elizabeth also came up with many of the variations: 3 different buttonholes, applied, built-in, corners, cast off, etc etc. (btw, Zimmermann has two n’s at the end.). Knit On…


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