Cast on and join in the round

Start by casting on between 60 and 80 stitches on your circular needles — the exact number depends on your sock size and yarn weight. Use a long-tail cast-on or any method you prefer; the key is that your stitches sit evenly around the needle. Most sock patterns call for 64 stitches as a standard adult size.

Once all stitches are on the needle, slide them to the center of the cable so they sit loosely. Hold the needle so the working yarn (the end attached to your ball) is on the right side. Bring the two needle tips together and knit the first stitch using the working yarn. This connects your cast-on edge into a circle. Place a stitch marker on the right needle tip to mark the start of your round — you will pass this marker every time you complete a full circle.

Pull the working yarn snug after your first few stitches to close any gaps at the join. The cast-on edge should form a smooth ring with no twists running through it. If you see a twist, pull out and start over before you knit further.

Key Takeaways

  • Cast on 60 to 80 stitches depending on foot size, then join in the round by knitting the first stitch with the working yarn.
  • The cuff and leg are worked in stockinette stitch (knit every round) or ribbing (alternating knit and purl) for 1 to 2 inches.
  • The heel flap is worked flat on half your stitches while the other half waits on the cable, then you turn and work back and forth in rows.
  • After the heel turn, you pick up stitches along the sides of the flap and decrease back to your original stitch count over several rounds.
  • The foot is worked in stockinette until the sock reaches your toe, then you decrease at each side until 8 stitches remain and graft them closed.

Work the cuff and leg

Knit every round in stockinette stitch (knit all stitches) or work a ribbed cuff if you prefer more stretch. A 1x1 rib (one knit, one purl) or 2x2 rib (two knit, two purl) both work well. Ribbing grips the leg better than stockinette and looks finished, though it takes slightly longer to knit.

Continue for 1 to 2 inches, depending on how tall you want the cuff. Most socks have a cuff between 1 and 1.5 inches. Count your rounds by marking every tenth round with a pen on a piece of paper, or use a row counter if you have one. When you reach your target height, you are ready to divide for the heel.

Divide stitches and work the heel flap

The heel is worked flat (back and forth in rows) on half your stitches while the other half waits. If you cast on 64 stitches, you will work the heel on 32 stitches. Slip the first 32 stitches onto one needle tip and leave the remaining 32 stitches on the cable — these become your instep and will wait while you finish the heel.

Attach your yarn to the first stitch of the heel stitches and knit across all 32 heel stitches. Turn your work and purl back across. Now you are working flat in rows instead of in a round. Continue knitting one row and purling the next for 24 to 32 rows total — aim for a heel flap that is roughly square when you look at it. A good rule is to work until the flap is about as tall as it is wide.

On every knit row, slip the first stitch knitwise without knitting it. This creates a chain edge that is easier to pick up stitches from later. Purl the last stitch of every purl row for the same reason.

Turn the heel

The heel turn is a series of short rows that shape the heel cup. You will knit partway across, then turn and purl partway back, gradually working more stitches into each row until you have used all the heel stitches.

On your first short row, knit 18 stitches (roughly half your heel stitches plus 2), then slip 1 and purl 1, then turn. Purl back 11 stitches, slip 1 and knit 1, then turn. From here, knit across to one stitch before the gap from your last turn, slip 1 and purl 1, then turn. Purl back to one stitch before the gap, slip 1 and knit 1, then turn. Repeat this pattern — always working one more stitch before the gap — until you have worked all your heel stitches. You should end with roughly 18 stitches remaining in the heel.

Pick up stitches and decrease to the foot

After the heel turn, you return to working in the round. With the working yarn attached to your heel stitches, knit across all remaining heel stitches. Then pick up stitches along the right side of the heel flap — one stitch for every two rows you knitted. If your flap was 24 rows, pick up 12 stitches. Use the chain edge you created by slipping the first stitch of each row.

Knit across your instep stitches (the 32 that were waiting on the cable). Then pick up the same number of stitches along the left side of the heel flap. You now have roughly 76 stitches on your needles — more than you started with. Knit one full round without decreasing to establish your new round.

On the next round, decrease one stitch on each side of the foot by knitting two stitches together at the end of the heel stitches and slipping one stitch before the instep, then knitting the next stitch and passing the slipped stitch over it. Repeat this decrease round every other round until you are back to 64 stitches. You are now ready to knit the foot.

Knit the foot to the toe

Work in stockinette stitch (knit every round) until the sock reaches your toe. Measure from the back of your heel to your toe bone — this is roughly how long your foot section should be. Most adult socks need 6 to 8 inches of foot length before the toe shaping begins.

To find the right stopping point, try the sock on. The toe shaping should start where your toes begin, not at the tip of your foot. If you are knitting for someone else, measure their foot from heel to toe and subtract about half an inch for the toe shaping.

Decrease for the toe and graft the end

Once you reach the toe, you will decrease at each side of the foot until only 8 stitches remain. On the first decrease round, knit 1, slip 1 and knit 1 and pass the slipped stitch over (a left-leaning decrease), knit to 3 stitches before the instep, knit 2 together (a right-leaning decrease), knit 1. Repeat the same decreases on the instep side. You have now decreased 4 stitches in one round.

Knit one round without decreasing. Then repeat the decrease round. Continue this pattern — one decrease round, one plain round — until you have 8 stitches left (2 on each quarter of the sock). Cut your yarn, leaving a 6-inch tail. Thread the tail through a tapestry needle and graft the remaining stitches closed using the Kitchener stitch, which creates an invisible seam. Insert the needle through the first stitch on one needle as if to purl, then through the first stitch on the other needle as if to knit. Continue alternating and slipping stitches off as you go until all 8 stitches are closed.

Weave in ends and finish

After grafting, weave the yarn tail back through the stitches near the toe using your tapestry needle. This anchors it and hides it inside the sock. Weave in any other loose ends from your cast-on or color changes. Trim the tails close to the fabric.

Try on your finished sock. The heel should sit at your actual heel, the foot should feel snug but not tight, and the cuff should stay up without rolling down. If the fit is off, note what needs adjusting for your next pair — socks are forgiving, and small changes in cast-on number or leg length make a big difference in the final fit.

Frequently Asked Questions

What size circular needles do I need?

Use needles one to two sizes smaller than the needle size your yarn calls for on the label. Socks need tight gauge to hold their shape and stay up. If your yarn says size 6 needles, try size 4 or 5. The needle length should be 16 inches or shorter so the stitches do not spread too far apart.

Can I use straight needles instead of circular needles?

Straight needles make socks much harder because you have to work the leg and foot in rows (back and forth) rather than rounds, which means you will have seams to sew. Circular needles let you knit in a continuous spiral with no seams. If you only have straight needles, you can knit a sock, but circular needles are worth buying.

What do I do if I drop a stitch in the middle of the sock?

If you notice a dropped stitch within a few rounds, pick it up with a crochet hook by catching the loop and pulling it back through each row above it until it sits on your needle again. If the drop is more than a few rows down, you may need to unravel back to that point and reknit, or leave it and accept a small ladder run in that spot.

How do I know when my heel flap is the right length?

Count your rows and aim for 24 to 32 rows depending on foot size. A quick visual check: the flap should look roughly square when you hold it up. If it looks taller than it is wide, you have worked too many rows. If it looks wider than it is tall, work a few more rows.

Do I have to use the Kitchener stitch to close the toe?

Kitchener stitch creates the neatest finish, but you can also knit the remaining 8 stitches together in pairs (4 decreases) and cut the yarn, then weave the tail through the hole. This leaves a small bump at the toe, which is fine if you do not mind the look. Kitchener stitch is worth learning because it looks invisible.