Casting off secures the last row of stitches so your knitting doesn't unravel

Casting off (also called binding off) is how you finish a knitted piece by locking the final row of stitches in place. Without it, pulling the yarn would cause every stitch to come undone. The basic method takes about a minute per row and works on any stitch type—garter, stockinette, ribbing, or anything else.

The standard cast-off is the one you'll use most often. You knit two stitches, pass the first stitch over the second, then repeat across the row. This creates a chain-like edge that's slightly elastic and sits flat on most projects.

Key Takeaways

  • The basic cast-off involves knitting two stitches, then pulling the first stitch over the second and off the needle, repeating to the end of the row.
  • Cast off on the same size needle you used for the body of the project, or one size larger if your cast-off edge tends to pucker.
  • Leave a tail of yarn 4 to 6 inches long after you cast off the final stitch, then thread it through the loop to find it.
  • Different cast-off methods exist for ribbed edges, stretchy projects, and decorative finishes, but the basic method works for most everyday knitting.

The basic cast-off step by step

Start with your working yarn attached to the stitches on your needle. Knit the first two stitches normally—insert the needle, wrap the yarn, and pull through to create two new stitches on the right needle.

Insert the left needle into the first stitch on the right needle (the one you knit first). Lift that stitch up and over the second stitch and off the needle entirely. You now have one stitch on the right needle. Knit one more stitch from the left needle, then repeat: insert the left needle into the first stitch on the right needle, lift it over the second stitch, and drop it off.

Continue this pattern—knit one, pass the previous stitch over—until you reach the end of the row. When only one stitch remains on the right needle, cut the yarn, leaving a tail about 4 to 6 inches long. Pull the tail through the final loop and tighten it. That loop is now locked and won't come undone.

Needle size and tension matter for a neat edge

If your cast-off edge looks tight or puckered, switch to a needle one size larger for the cast-off row only. This gives the edge more room to breathe and prevents it from curling or bunching. Many knitters automatically go up one size for cast-off, even if their tension is normally fine.

Work the cast-off at the same pace as the rest of your knitting—not too tight, not too loose. If you tend to knit tightly, consciously relax your hands. If you knit loosely, the cast-off will be floppy and won't hold the edge securely.

What to do with the yarn tail after casting off

After you pull the final loop tight, you have a loose yarn tail. Thread this tail onto a tapestry needle (a blunt needle with a large eye). Weave the tail through the bumps on the back of the cast-off edge for about an inch, then weave back in the opposite direction. This anchors the tail so it won't slip out.

Trim the tail to about half an inch from the edge. If you leave it too long, it will show; if you trim it too short, it may work loose over time. For projects that will get a lot of wear—socks, sweaters, bags—weave the tail in a bit longer to be safe.

Cast-off methods for ribbed and stretchy projects

If you're finishing a ribbed edge (like the cuff of a sock or the hem of a sweater), the standard cast-off can look stiff. Instead, knit the stitches as they appear: knit the knit stitches and purl the purl stitches as you cast off. This keeps the ribbing pattern intact and the edge stays flexible.

For projects that need extra stretch—like the top of a sock or a hat brim—the suspended bind-off works better. Instead of passing one stitch over another, you slip stitches and pass them over in a different order, creating a looser, more elastic edge. This takes a bit longer but is worth learning if you knit socks or fitted garments regularly.

Common mistakes and how to avoid them

The most common error is casting off too tightly, which makes the edge pucker and prevents the piece from lying flat. If this happens to you, practice relaxing your tension or move up a needle size. You can also try knitting the cast-off stitches a bit looser than the rest of the row.

Another mistake is not leaving a long enough yarn tail. If you cut the yarn too close to the final loop, the loop can slip and unravel the last few stitches. Always leave at least 4 inches so you have enough to thread and weave in securely.

Some knitters accidentally cast off on the wrong side of the fabric or forget to cast off entirely and just cut the yarn. Check that you're working on the correct row and that you've completed the cast-off before cutting.

When to cast off and when to leave stitches live

Cast off when you've finished a piece and won't be picking up stitches from that edge again. For example, cast off the top of a hat, the end of a scarf, or the cuff of a sleeve.

Leave stitches live (on the needle or on a stitch holder) if you plan to pick them up later—for example, when you're knitting a sweater in pieces and need to join the sleeves to the body, or when you're adding a border or ribbing to an edge. Live stitches can sit on a holder or a piece of scrap yarn for weeks without damage.

Frequently Asked Questions

Can you cast off on a purl row instead of a knit row?

Yes. If your pattern ends on a purl row, purl the stitches as you cast off instead of knitting them. The method is identical—purl two stitches, pass the first over the second, repeat. The edge will look slightly different but will be just as find.

What if you accidentally cast off too tightly and the edge won't stretch?

If the piece is finished and the edge is unusable, you can carefully cut the cast-off edge and pick the stitches back up onto a needle, then cast off again using a larger needle or looser tension. This takes patience but is fixable. For future projects, practice the cast-off on scrap yarn first.

Do you have to weave in the yarn tail right after casting off?

No. You can leave the tail loose and weave it in later, even days later. Some knitters prefer to finish all the knitting first, then weave in all the tails at once. Just keep track of which tail belongs to which piece.

Is there a cast-off method that looks like the cast-on edge?

The Kitchener stitch (also called grafting) creates an invisible seam and is often used to join two live edges so they look like one continuous piece. It's more advanced than basic cast-off but creates a seamless finish on socks, sweaters, and other projects where you want the top and bottom to match.