What Decreasing Means and Why You Need It

Decreasing is the technique of combining two or more stitches into one stitch, which reduces the total stitch count on your needle. You use decreases to shape your knitting — narrowing sleeves, tapering the crown of a hat, creating diagonal lines in colorwork, or finishing the edges of garments. Without decreases, every piece you knit would be a rectangle.

The most common decreases are knit two together (K2tog), slip-slip-knit (SSK), and purl two together (P2tog). Each one combines two stitches into one, but they lean in different directions and create different visual effects. Learning which decrease to use and where to place it is what separates a flat, shapeless piece from a garment that actually fits.

Key Takeaways

  • Knit two together (K2tog) is the simplest decrease and leans to the right; slip-slip-knit (SSK) leans to the left and is often paired with K2tog for balanced shaping.
  • Insert your needle through two stitches at once, then knit or purl them as if they were one stitch to complete a decrease.
  • Decreases work best when placed one or two stitches in from the edge, which makes them visible and creates a neat selvage.
  • Matching your decrease direction to your pattern's design — right-leaning decreases on the right side, left-leaning on the left — creates a professional, intentional look.
  • Practice decreases on a small swatch before starting a shaped garment so you can feel the rhythm and see how they change the fabric.

Knit Two Together (K2tog) — The Right-Leaning Decrease

Knit two together is the most straightforward decrease and the one most patterns call for first. Insert your right needle through the next two stitches on your left needle from left to right, as if you were going to knit them normally. Wrap your yarn and knit both stitches as a single stitch. You now have one stitch on your right needle instead of two.

K2tog creates a decrease that visually leans to the right. This matters because when you look at your finished fabric, the decrease line will slant in a particular direction, and that direction should match your pattern's design. On the right side of a garment, a right-leaning decrease looks natural. On the left side, a left-leaning decrease (like SSK) usually looks better because it mirrors the shaping.

Common mistake: inserting your needle from right to left instead of left to right. This twists the stitch and creates a loose, uneven decrease. Always enter from the left side of both stitches.

Slip-Slip-Knit (SSK) — The Left-Leaning Decrease

Slip-slip-knit is a two-step decrease that leans to the left. First, slip one stitch knitwise (as if to knit) from your left needle to your right needle. Then slip the next stitch knitwise as well. Now you have two stitches on your right needle, both slipped. Insert your left needle through both slipped stitches from left to right and knit them together. This creates one stitch that leans left.

SSK takes a moment longer than K2tog because of the two slip steps, but it creates a mirror-image decrease. When you use K2tog on the right edge and SSK on the left edge of a sleeve or cardigan front, the shaping looks balanced and intentional. Many patterns pair these two decreases specifically for this reason.

Common mistake: slipping the stitches purlwise instead of knitwise. Slipping purlwise twists the stitch in the wrong direction and ruins the lean. Always slip knitwise for SSK.

Purl Two Together (P2tog) — Decreasing on the Wrong Side

When you are working in the round or on a purl row, you use purl two together instead of knit two together. Insert your right needle through two stitches on your left needle from right to left (the opposite direction from K2tog), then purl both stitches as one. The result is a single stitch on your right needle.

P2tog leans to the right when viewed from the knit side of the fabric. This means if you are working flat and decreasing on a wrong-side (purl) row, a P2tog on the wrong side will create a left-leaning decrease on the right side of your finished piece. Patterns sometimes use this to avoid having to work SSK on the knit side.

When you are working in the round, you see both sides of your fabric as you knit, so you can use P2tog on purl rounds the same way you would use it on purl rows — to create a decrease that leans the direction you want on the knit side.

Where to Place Decreases for Clean Edges

Decreases work best when they are not placed right at the edge of your piece. Instead, work one or two stitches in stockinette stitch, then place your decrease, then continue to the end of the row. This creates a neat selvage — the edge of your fabric stays clean and even, and the decrease line sits visibly inside the edge where it belongs.

For example, on a sleeve cap decrease row, you might work: knit one, knit two together, knit to the last three stitches, slip-slip-knit, knit one. This places one decrease one stitch in from each edge. The single stitch on either side acts as a border, and the decreases create a balanced, shaped line.

If you place a decrease right at the edge (knit two together as your first stitch), the edge becomes uneven and the decrease line disappears into the selvage. Your shaping still works mathematically, but it looks sloppy and unprofessional.

Decreasing Multiple Stitches in One Row

Many patterns ask you to decrease more than one stitch per row — for example, "decrease 5 stitches evenly across the row." This means you divide your total stitches by the number of decreases you need to make, then space them out evenly. If you have 60 stitches and need to decrease 5 stitches, you would decrease roughly every 12 stitches.

Work your decreases the same way you would work a single decrease: one or two stitches in, then the decrease, then continue. If you are decreasing on both edges (like on a sleeve), place one decrease near each edge and space the remaining decreases evenly across the middle of the row.

A common pattern instruction is "decrease 1 stitch at each edge every other row." This means on every other row (usually every other knit row if you are working flat), you work a decrease one stitch in from each edge. You do this for as many rows as the pattern specifies. This creates a gradual taper that looks smooth and intentional.

Practice Decreases on a Swatch Before You Start

Before you begin a shaped garment, knit a small swatch — about 20 stitches by 20 rows — and practice your decreases on it. Cast on, knit a few rows in stockinette stitch, then work a decrease row: knit one, K2tog, knit to the last three stitches, SSK, knit one. Repeat this decrease row every other row for several rows. Bind off and look at what you made.

A practice swatch shows you exactly how your decreases will look in your finished piece. You will see whether your tension is even, whether your decreases are leaning the right direction, and whether you are placing them in the right spot. It also builds muscle memory so that when you start your actual project, the decreases feel automatic and you can focus on following the rest of the pattern.

Keep your swatch. You can refer back to it later if you forget how a particular decrease should look or feel, and it serves as a record of your tension and technique for that yarn and needle size.

Frequently Asked Questions

What is the difference between K2tog and SSK?

K2tog leans to the right; SSK leans to the left. Both combine two stitches into one. Patterns often pair them on opposite edges of a piece to create balanced, symmetrical shaping. K2tog is faster because it is one step instead of two.

Can I use K2tog on both edges of a sleeve instead of mixing it with SSK?

Technically yes, but the shaping will look unbalanced. Both decreases will lean the same direction, so one edge will look intentional and the other will look accidental. Using K2tog on one edge and SSK on the other creates a professional, mirror-image effect that most patterns rely on.

What does "decrease 1 stitch at each edge" mean?

It means work one decrease one or two stitches in from the left edge and one decrease one or two stitches in from the right edge on the same row. This removes two stitches total from that row and is the standard way to shape sleeves and armholes.

Do I count the decrease as one stitch or two when I am following a pattern?

Count it as one stitch. When you knit two stitches together, you remove one stitch from your total count. If your pattern says "you should have 50 stitches," and you just worked a row with two decreases, you went from 52 stitches to 50.

Why does my decrease row look loose or uneven?

The most common cause is inserting your needle in the wrong direction. For K2tog, enter from left to right. For SSK, slip knitwise (as if to knit), not purlwise. Also check that you are not pulling your yarn too tight or too loose after the decrease — the tension should match the rest of your fabric.