The Ins and Outs of Knitting & Crochet: Increases and Decreases

Shaping is the foundation of any well-fitting hand-knit or crocheted garment. Understanding the mechanics of how increases and decreases lean and behave is what allows you to transform flat fabric into structured, comfortable wear. Whether you are curving the armholes of an organic cotton summer tank or shaping the crown of a linen sun hat, clean shaping relies on precision and technique. In this guide, I’ll walk you through the most reliable increase and decrease methods for both knitting and crochet, explaining the structural reasons behind each one so you can shape your projects with confidence.

Increasing

Adding stitches to your fabric expands its width, allowing you to build sleeves, flare out skirts, or build three-dimensional shapes like reusable market bags and amigurumi. When we increase, we are either working multiple stitches into a single loop or creating entirely new loops from the space between existing stitches. Each method behaves differently—some leave decorative eyelets, while others blend seamlessly into the fabric. Finding a rhythm with these additions can be deeply satisfying, keeping your mind engaged as the pattern grows.

Knitting Increases

Before working these increases, ensure you have a solid grasp of your basic knit and purl stitches. If you need a quick refresher, check our Knit and Purl Stitch Guide.

• Knit Front and Back (KFB): A straightforward method where you knit into the front loop of a stitch, leave it on the needle, and then knit into the back loop of the same stitch. This creates a small, horizontal bar (resembling a purl stitch) on the front of your work. It is highly secure and works beautifully for textured, plant-based fabrics where you don't mind a visible line of increase.
• Make One Left (M1L) & Make One Right (M1R): These are nearly invisible increases. They are worked by using your left needle tip to lift the horizontal strand running between your active needles. For a M1L, lift the bar from front to back and knit through the back loop to twist the stitch and prevent a hole. For a M1R, lift the bar from back to front and knit through the front loop. Twisting the stitch is the secret to keeping the fabric solid and neat.
• Yarn Over (YO): The simplest way to add a stitch, created by wrapping the yarn over your right needle before working the next stitch. This leaves a decorative hole (an eyelet) in the fabric. If you want to see how to pair yarn overs with decreases to create beautiful structures, read our guide on Lace Knitting Basics: A Guide to Yarn Overs and Leaning Decreases.

Crochet Increases

Crochet increases are generally straightforward because we work directly into the loops of the row below. They are essential for shaping hats, bags, and blankets. If you are starting a project in the round, such as a reusable cotton basket, you can read our tutorial on the Magic Ring and Circular Cast-On to begin your work cleanly.

• Basic Crochet Increase: Simply work two stitches into the same stitch of the previous row. You can apply this to double crochet, half treble, or treble crochet stitches. It is a robust increase that adds width quickly, though it can leave a slightly visible bump.
• Invisible Increase: A brilliant technique for dense, structural items like amigurumi made from organic cotton. Instead of working under both loops, work the first double crochet into the front loop only, and then work the second double crochet through both loops of the same stitch. This softens the transition and keeps the fabric flat and tight.
• Chain Space Increase: By working a chain stitch between your active stitches without skipping any stitches below, you create a new stitch space. This leaves a neat, decorative eyelet in your fabric, similar to a yarn over in knitting, and is ideal for light, breathable summer shawls.

Decreasing

Decreasing reduces your stitch count, drawing the fabric inward to create angles, slopes, or curves. It is the key to shaping the shoulders of a linen vest, tapering the sleeves of a cotton cardigan, or closing the top of a hat. Because decreases pull stitches together, they naturally lean either to the left or the right. Understanding this directionality lets you control the lines of your design, ensuring your shaping looks deliberate and clean. Take your time with these decreases; keeping your tension even is the key to a professional finish.

Knitting Decreases

When decreasing in knitting, the order in which the stitches are worked determines which way the decrease leans. Mirroring these decreases on either side of a garment is what gives hand-knitted items their professional, balanced look.

• Knit Two Together (K2tog): Insert your right needle into the next two stitches on your left needle at the same time, from front to back, and knit them together. Because the needle enters the second stitch first, this decrease leans to the right. It is the most common decrease and is often paired with SSK for mirrored shaping. For more detail, see our tutorial on Knit 2 Together (K2tog).
• Slip Slip Knit (SSK): Slip two stitches individually knitwise from the left needle to the right needle. Insert the left needle back into the front of these two slipped stitches and knit them together through the back loops. This twists the stitches slightly and causes the decrease to lean to the left.

Crochet Decreases

In crochet, decreases are made by pulling up loops in multiple stitches and joining them together. This keeps the height of your row consistent while reducing the stitch count.

• Basic Crochet Decrease (e.g., dc2tog, tr2tog): Insert your hook into the first stitch, yarn over, and pull up a loop. Leave this loop on the hook, then insert the hook into the next stitch, yarn over, and pull up another loop. Yarn over once more and pull through all loops on the hook. This merges two stitches into one. You can perform this as a double crochet two together (dc2tog) or a treble crochet two together (tr2tog).
• Invisible Decrease (for Double Crochet): Insert your hook into the front loop only of the first stitch, then immediately insert it into the front loop only of the second stitch. Yarn over, pull through both front loops, yarn over again, and pull through the remaining two loops on your hook. This is excellent for keeping stuffing inside amigurumi and creating a smooth, flat surface.
• Skipping Stitches: In openwork patterns, you can simply skip a stitch to decrease your stitch count. When worked at the edge of a row, skipping a stitch creates an angled decrease, which is particularly useful for light linen cardigans or lacy plant-fibre shawls.

The Aesthetic Value of Stitch Manipulation

Increases and decreases aren't just functional; they are also highly decorative. By combining them in structured sequences, you can create intricate lace, textured cables, or chevron stripes. For instance, working a yarn over followed immediately by a leaning decrease maintains your stitch count while creating a delicate eyelet. Plant-based fibres like linen and organic cotton excel here, providing the crisp stitch definition needed to make these openwork details stand out. In contrast, brioche knitting relies on paired increases and decreases to create its signature thick, wavy ridges.

Mastering these techniques gives you complete control over your fabric. If you want to design your own custom-fit tee or accessory, you can use purlJam, our pocket-sized digital studio, to generate the pattern and calculate your increases and decreases automatically. And if you are trying to find the perfect project to use up leftover plant-based yarn, our guide on Taming the Stash: 3 Strategic Systems for Yarn Organisation will help you organize your workspace and plan your next cast-on.

Happy Crafting 🧶

Need a visual guide? You can print out our "Stitch Direction Cheat Sheet" infographic (coming soon), which maps out Left-Leaning vs. Right-Leaning increases and decreases side-by-side to keep next to your crafting chair.

Frequently Asked Questions

How do I prevent holes when making a 'Make One' (M1) increase in knitting?
To prevent a hole, you must twist the lifted bar as you knit it. For a Make One Left (M1L), lift the bar from front to back and knit through the back loop. For a Make One Right (M1R), lift the bar from back to front and knit through the front loop.

Why do my decreases look loose or bumpy, and how do I fix them?
Decreases can sometimes look slightly uneven, especially when working with inelastic plant-based fibres like linen or organic cotton. Keep your tension consistent, work close to the needle tips, and do not pull too tightly. Trust the blocking process to wash and settle the stitches flat when your project is finished.

What is the difference between a standard double crochet decrease (dc2tog) and an invisible decrease?
A standard dc2tog works through both loops of two consecutive stitches, creating a visible double-thickness bar. An invisible decrease works only through the front loops of those two stitches before completing the double crochet, resulting in a flat, seamless finish that is ideal for amigurumi.

How do I know which direction a knit decrease will lean?
The direction depends on how the stitches are entered and worked. A Knit Two Together (K2tog) leans to the right because you enter the second stitch first, pulling it to the right. A Slip Slip Knit (SSK) leans to the left because slipping the stitches knitwise twists their orientation before they are knit together through the back loops.