A slip knot is the loop you tie first to anchor yarn to your needle
A slip knot is a loop of yarn that slides onto your needle and holds the yarn in place while you cast on. It is not a finished stitch—it is the anchor point. You tie it before you do anything else, and it sits on your needle as your first loop. Once you cast on your stitches, the slip knot becomes your first actual stitch.
The slip knot is straightforward to tie and takes about 10 seconds. The loop must be loose enough to slide onto your needle but tight enough that it does not fall off. If you pull it too tight, you will struggle to work your cast-on stitches. If you leave it too loose, it will slip off the needle before you are ready.
Key Takeaways
- A slip knot is a temporary loop that anchors your yarn to the needle before you cast on stitches.
- You tie the slip knot with the yarn tail and the working yarn (the yarn still attached to the ball or skein).
- The loop should be snug on the needle but loose enough to slide and work with easily.
- If your slip knot is too tight, your first cast-on stitches will be difficult to work; if too loose, it will fall off the needle.
Step-by-step: tying a slip knot
Start with the yarn in your hand. You will be working with two lengths: the yarn tail (the short end you leave hanging) and the working yarn (the long end attached to your ball or skein). Most knitters leave a tail about 4 to 6 inches long, though you can adjust this depending on your cast-on method.
Make a loop by crossing the working yarn over the yarn tail. The working yarn should pass over the top of the tail, forming a circle. Hold this loop loosely between your thumb and index finger so it does not collapse.
Pull the working yarn through the loop from underneath. Reach through the circle with your fingers or a needle and grab the working yarn, then pull it back through the loop. You now have a new loop on top of the original one.
Slide this new loop onto your needle and tighten gently. Pull both the yarn tail and the working yarn to snug the knot around the needle. The knot should sit firmly but not so tight that you cannot move it or work your cast-on stitches. If it feels too tight, loosen it slightly by pulling the working yarn gently away from the knot.
Common mistakes and how to fix them
The most frequent error is tightening the slip knot too much. New knitters often pull hard on both ends of the yarn, which locks the knot so tightly that the first cast-on stitches become cramped and difficult to work. If this happens, loosen the knot by holding the needle still and gently pulling the working yarn away from the knot until you have room to work.
Another mistake is making the loop too large. If the loop is very loose, it will slide off the needle before you finish casting on. The loop should be just large enough to fit over your needle with a little room to spare. If yours is too big, untie it and start over—it only takes a few seconds.
Some knitters also tie the knot in the wrong direction, creating a loop that does not sit flat on the needle. If your slip knot looks twisted or bunched, untie it and retie it, making sure the loop sits smoothly around the needle shaft.
Where the slip knot sits in your cast-on process
The slip knot is your first step, before any cast-on method. Once the slip knot is on your needle, you then perform your chosen cast-on (long-tail cast-on, cable cast-on, or another method). Each cast-on method uses the slip knot as the starting point and builds stitches from there.
After you finish casting on all your stitches, the slip knot becomes your first actual stitch. When you begin knitting the first row, you will work into the slip knot just as you would any other stitch. It is not removed or replaced—it straightforward becomes part of your fabric.
Adjusting the slip knot if it is too tight or too loose
If you realize mid-cast-on that your slip knot is too tight, stop and fix it before you go further. Hold the needle steady with one hand and gently pull the working yarn (the long end) away from the knot with the other hand. This loosens the knot without untying it. You should feel it relax around the needle.
If the knot is too loose and keeps sliding, tighten it by pulling both the yarn tail and the working yarn gently and evenly. Do not yank—a steady, gentle pull is enough. The knot should move slightly on the needle but not fall off when you tug on it lightly.
If the knot is so far gone that you cannot fix it by adjusting, straightforward untie it and tie a new one. There is no penalty for starting over, and a fresh slip knot takes only seconds.
Why the slip knot matters for your cast-on
The slip knot sets the tone for your entire cast-on. If it is too tight, your first row of stitches will be cramped and hard to work, and your edges may look uneven. If it is too loose, you risk dropping stitches before you even begin. A properly tied slip knot—snug but workable—makes the rest of the cast-on smooth and your first row much easier to knit.
The slip knot also affects the appearance of your finished edge. A knot that is too tight can create a visible bump or pucker at the edge of your work. A well-balanced slip knot sits invisibly as part of your first stitch, and your edge looks clean and even.
Frequently Asked Questions
Can I use a slip knot with every cast-on method?
Yes. Every cast-on method starts with a slip knot on the needle. Some methods, like the long-tail cast-on, use the slip knot as the anchor while you create new stitches with the yarn tail. Others, like the cable cast-on, build stitches next to the slip knot. The slip knot is always your first loop.
What if my slip knot keeps falling off the needle?
The loop is too loose. Untie it and tie a new one, pulling both the yarn tail and working yarn a bit tighter this time. The knot should be snug enough that it does not slide when you tug gently on the yarn, but not so tight that you cannot move it or work your cast-on stitches.
Do I count the slip knot as one of my cast-on stitches?
Yes. The slip knot is your first stitch. If a pattern says to cast on 20 stitches, you tie the slip knot and then create 19 more stitches, for a total of 20 on the needle. Some patterns say "cast on 20 stitches plus a slip knot," which means you create 20 stitches in addition to the knot, giving you 21 total.
Can I tie the slip knot on the yarn ball end instead of the tail?
No. The slip knot must be tied using the yarn tail (the short end you leave hanging) and the working yarn (the long end attached to the ball). If you tie it the other way, you will run out of working yarn almost when ready and have no yarn left to knit with.
How tight should the slip knot be around the needle?
Tight enough that it does not slide off when you gently tug the yarn, but loose enough that you can move it along the needle and work your cast-on stitches without strain. If you cannot slide the loop slightly with your finger, it is too tight. If it falls off with a light tug, it is too loose.