The Basic Heel Turn: What You're Actually Doing

A sock heel is a short, dense section of knitting that turns the corner from your leg down to your foot. Instead of knitting in a continuous spiral, you work back and forth on a subset of stitches—usually half your total—to create a flap, then you pick up stitches along the edge of that flap to form the heel cup. The result is a reinforced corner that sits under your ankle and takes the wear that makes socks wear out fastest.

The most common method is called a flap-and-gusset heel, and it works the same way whether you're using four needles, two needles, or a circular needle. The steps are always: knit the flap, turn the heel, pick up stitches, and decrease the gusset. Timing varies by sock size, but expect the entire heel to take 30 to 45 minutes if you're working at a steady pace.

Key Takeaways

  • A heel flap is knitted flat (back and forth) on half your stitches while the other half wait on a needle or stitch holder.
  • The flap is usually worked in a slipped-stitch pattern to make it dense and durable, and you knit it until it's roughly as tall as it is wide.
  • The heel turn uses short rows to shape the corner, and you'll work fewer stitches with each row until you've turned the corner completely.
  • After the turn, you pick up stitches along both edges of the flap to close the gap and form the heel cup.
  • The gusset decrease brings your stitch count back down to your original number before you continue knitting the foot in the round.

Setting Up: Which Stitches Go Into the Heel

Before you start, you need to know how many stitches will form your heel flap. If you're working a sock on 64 stitches total, your heel flap uses 32 stitches—exactly half. If your total is an odd number, round down: 65 stitches means a 32-stitch flap.

Divide your stitches so that half are on one needle (or one section of your circular needle) and half are on another. The half that will become the flap stays active; the other half waits. If you're using four needles, this is straightforward—needles 1 and 2 hold the instep stitches, and needles 3 and 4 hold the heel stitches. If you're using a circular needle, place a marker between the two halves so you know where the division is.

Join a new length of yarn at the start of your heel stitches if you want to keep the leg yarn separate, or continue with your working yarn—both work. Some knitters prefer a new yarn because it makes it easier to pick up stitches later without tangling.

Knitting the Heel Flap

The heel flap is worked flat in rows, not in the round. You'll knit back and forth on your heel stitches only, ignoring the instep stitches completely until the flap is done.

The standard pattern for a durable flap is the slipped-stitch heel: on right-side rows, slip the first stitch, knit across, and purl the last stitch. On wrong-side rows, slip the first stitch, purl across, and knit the last stitch. This creates a chain of slipped stitches along both edges, which you'll use later to pick up stitches. The slipped stitches also make the flap denser and more resistant to wear.

Continue this pattern until your flap is roughly square—if you started with 32 stitches, knit until the flap is about 32 rows tall. This usually takes 15 to 20 minutes. A quick way to check: the flap should be as tall as it is wide when you measure it flat. You'll end on a wrong-side row (a purl row).

Turning the Heel with Short Rows

The heel turn is where the magic happens. You're going to knit back and forth on fewer and fewer stitches until you've created a curve that turns the corner from leg to foot. This uses a technique called short rows—you knit partway across, turn around, and knit back without working all the stitches.

Start on a right-side row. Knit across about two-thirds of your heel stitches (roughly 21 stitches if you have 32). On the next stitch, work a wrap and turn: slip one stitch to the right needle, bring the yarn forward, slip the stitch back to the left needle, and turn your work. This wrap prevents a hole from forming at the turn point. Purl back across to about two-thirds of the way, wrap and turn the next stitch, and turn again.

Continue this pattern, working one fewer stitch before each wrap and turn, until you've worked down to roughly the middle third of your stitches. Then reverse: work one more stitch before each wrap and turn, gradually working back out to the full width. When you've worked all stitches and wrapped the last one, you're done turning the heel. This takes about 10 to 15 minutes and requires focus—if you lose track of how many stitches you're working, count them before each row.

Picking Up Stitches for the Gusset

Now you'll pick up new stitches along both edges of the flap to close the gap between the heel and the instep. This is where those slipped stitches pay off—they create a clear line to pick up from.

With your working yarn, pick up one stitch in each slipped stitch along the left edge of the flap. If your flap is 32 rows tall, you'll pick up roughly 16 stitches (one for every two rows). Then knit across your waiting instep stitches. Then pick up stitches along the right edge of the flap the same way. You now have roughly 16 + 32 + 16 = 64 stitches again, but they're distributed unevenly: the heel and gusset have more stitches than they should.

This is normal. You'll decrease back down to your original stitch count over the next few rounds.

Decreasing the Gusset

The gusset decrease brings your stitch count back to normal and shapes the heel so it fits your foot properly. You'll work in the round again, and on each round you'll decrease one stitch on each side of the heel.

Knit one full round without decreasing—this stabilizes the picked-up stitches. On the next round, knit to the last 3 stitches of the heel section, knit 2 together, knit 1. Then knit across the instep. Then knit 1, slip 1, knit 1, pass the slipped stitch over (a left-leaning decrease). Repeat this decrease round every other round until you're back to your original stitch count. For a 64-stitch sock, this takes about 8 rounds and roughly 15 to 20 minutes.

When you've finished decreasing, you're ready to knit the foot of the sock in stockinette stitch until it reaches your toe. The heel is complete.

Common Mistakes and How to Avoid Them

The most common error is making the heel flap too short. If it's less than square, the heel cup won't cover your ankle properly and the sock will slip. Measure your flap against your stitch count before you start the turn—if you have 32 stitches, aim for at least 30 rows.

Another frequent mistake is losing track during the short-row turn. If you forget to wrap a stitch, you'll end up with a hole. Write down your stitch count before each row, or use a row counter. If you do miss a wrap, you can fix it later by working a yarn-over in that spot and decreasing it away on the next row.

Picking up too many or too few stitches along the flap edges creates an uneven gusset. Aim for one stitch per two rows of the flap. If you pick up too many, you'll have extra stitches to decrease; if you pick up too few, the gusset will be tight and uncomfortable.

Frequently Asked Questions

Can I use a different heel method, like a short-row heel?

Yes. A short-row heel (worked in the round without a separate flap) is faster and uses fewer stitches, but it's less durable because there's no reinforced flap. A flap-and-gusset heel is the traditional choice for everyday socks because the extra fabric wears longer. Try both and see which you prefer.

What if I accidentally knit the instep stitches while working the flap?

Stop when ready and tink back (undo stitches one at a time) to the point where you picked up the instep stitches. The instep must stay on a separate needle or holder until the heel is complete. If you've already gone several rows, it's faster to cut the yarn and start the flap over.

How do I know if my heel is the right size?

The heel should fit snugly around your ankle without bunching or gapping. If the gusset is too loose, you decreased too slowly; if it's too tight, you decreased too fast. On your next sock, adjust by decreasing every round instead of every other round (tighter) or every third round (looser).

Do I have to wrap and turn, or can I just turn without wrapping?

You can turn without wrapping, but you'll get a small hole at each turn point. Wrapping takes an extra second per stitch and prevents the hole entirely. It's worth learning.

What happens if I run out of yarn in the middle of the heel?

Join a new ball of yarn at the start of a row, leaving a 6-inch tail. Tie the old and new yarns together with a square knot, and weave the tails in later. Never join yarn in the middle of a row in a heel—the knot will be visible and uncomfortable under your foot.