What decreasing a stitch means and why you do it

A decrease is a knitting technique that removes one stitch from your needle, reducing the total stitch count on that row. You use decreases to shape your work — making sleeves narrower toward the wrist, tapering the sides of a sweater, or creating the crown shaping on a hat. Without decreases, every piece you knit would be a rectangle.

Decreases are the opposite of increases (which add stitches). Most knitting patterns tell you exactly where and how to decrease, but understanding the mechanics helps you follow those instructions and fix mistakes when they happen.

Key Takeaways

  • The most common decrease is knit two together (K2tog), which combines two stitches into one by knitting them as a single stitch.
  • Slip, slip, knit (SSK) is another standard decrease that leans the opposite direction from K2tog, letting you control how your shaping looks.
  • Your pattern will specify which decrease to use and where, because different decreases slant left or right and affect the fabric's appearance.
  • Decreases always happen on the knit side of your work, and you work them in the same row as your other stitches — no special setup needed.

Knit two together (K2tog) — the simplest decrease

Knit two together is the most straightforward decrease. Insert your right needle through two stitches on your left needle at the same time (instead of just one), then knit them together as if they were a single stitch. You now have one stitch on your right needle instead of two, and your stitch count has dropped by one.

K2tog slants to the right. If you look at your finished fabric, the decreased stitch leans toward the right side of your work. Patterns use this when they want the shaping to lean in that direction — often on the right edge of a garment piece or the right side of a centered decrease.

To practice: cast on 10 stitches, knit one row, then on the next row knit 4 stitches normally, then K2tog, then knit the remaining 4 stitches. You'll end with 9 stitches. Repeat this on every other row and watch your fabric narrow.

Slip, slip, knit (SSK) — the left-leaning decrease

SSK is a two-step decrease that leans to the left. Slip one stitch knitwise (as if you're about to knit it), slip a second stitch knitwise, then insert your left needle through both slipped stitches from left to right and knit them together. The result is one stitch on your right needle, and your stitch count drops by one.

Because of the way the stitches cross, SSK leans left — the opposite direction from K2tog. Patterns pair these two decreases on opposite sides of a garment to create balanced, symmetrical shaping. For example, a sweater might use SSK on the left edge and K2tog on the right edge so the shaping looks even.

SSK takes slightly longer than K2tog because it has two steps, but it becomes automatic with practice. The visual difference is worth the extra motion once you see how it improves the look of your finished piece.

Other decreases you'll encounter

Purl two together (P2tog) works exactly like K2tog but on the purl side of your work. If you're working in the round or on a purl row, you'll purl two stitches together instead of knitting them. It slants the same direction as K2tog.

Slip, slip, purl (SSP) is the purl-side version of SSK. Slip two stitches knitwise, return them to your left needle, then purl them together through the back loop. It's less common than SSK because many patterns avoid it, but you'll see it in some designs.

Double decreases (like central double decrease or CDD) remove two stitches at once. These are less common and usually appear in lace patterns or when you need to shape quickly. Your pattern will explain the specific steps if you need one.

Where decreases go in your pattern

Patterns write decreases in shorthand. You'll see "K2tog" or "SSK" in the row instructions, usually with a number telling you how many stitches to knit before the decrease. For example, "K5, SSK, K5" means knit 5 stitches, do an SSK decrease, then knit the remaining 5 stitches.

Decreases almost always happen on a knit row (the right side of stockinette stitch), not on purl rows. This is because decreases are easier to see and control on the knit side, and the shaping looks cleaner. If your pattern asks you to decrease on a purl row, it will say so explicitly.

The position of the decrease within the row matters for how your shaping looks. A decrease near the edge creates a slanted edge; a decrease in the middle of the row creates a centered shaping line. Your pattern positions them intentionally, so follow the instructions exactly.

Common mistakes and how to fix them

The most common mistake is accidentally knitting into the wrong loop when you slip stitches for SSK. If you slip knitwise (the standard way), your stitches will sit correctly. If you slip purlwise by accident, they'll twist and your decrease won't look right. Always slip knitwise unless your pattern specifically says otherwise.

Another mistake is decreasing too tightly. If you pull the yarn hard after a decrease, the stitch can look bunched. Decrease normally, then give the yarn a gentle tug to even out the tension. The stitch should sit smoothly on your needle.

If you realize you decreased in the wrong place, you can usually frog back (unravel) to that row and redo it. For a single misplaced decrease, you can also use a crochet hook to pick up the dropped stitch and ladder it back up, though this takes practice. Most knitters find frogging back one row is faster and safer.

Decreasing in different stitch patterns

In stockinette stitch (knit on the right side, purl on the wrong side), decreases are straightforward — you straightforward K2tog or SSK where the pattern tells you. The decrease sits cleanly against the smooth background.

In ribbed patterns, decreases can be trickier because you need to maintain the rib structure. If your rib is K2, P2 and you need to decrease, you might decrease two knit stitches together or two purl stitches together to keep the pattern balanced. Your pattern should specify this.

In lace patterns, decreases are essential to the design. Lace patterns often pair decreases with yarn overs (which add stitches) to keep the stitch count constant while creating the openwork design. Follow the pattern exactly — the decreases are part of the lace structure, not just shaping.

Frequently Asked Questions

What's the difference between K2tog and SSK?

K2tog slants right; SSK slants left. Both remove one stitch. Patterns use them on opposite sides of a garment to create balanced shaping. K2tog is slightly faster because it's one motion instead of two.

Can I decrease on a purl row?

Yes, but most patterns avoid it because decreases are harder to control on the purl side. If your pattern asks you to decrease on a purl row, use P2tog or SSP. It will say so in the instructions.

What if I decrease in the wrong place?

Frog back (unravel) to the row with the mistake and redo it. For a single stitch, you can also use a crochet hook to pick up the dropped stitch and ladder it back up, but frogging is usually faster and more reliable.

Do I need to decrease on every row?

No. Your pattern will tell you when to decrease — often every other row, or every fourth row, depending on how quickly you want to shape the piece. Follow the pattern instructions for the best results.

Why does my decrease look loose or bunched?

Tension is usually the cause. Decrease normally without pulling too hard, then give the yarn a gentle tug to even it out. If the stitch still looks wrong, you may have slipped in the wrong direction (purlwise instead of knitwise).