Cast-on

The cast-on is how you put the very first row of stitches onto the needle. Every pattern starts with "CO N sts" — where N is the number of stitches you need to begin.

The long-tail cast-on

Beginners usually learn the long-tail cast-on first. It's stretchy, looks clean, and is fast once you have the motion. The name comes from the tail you leave dangling: roughly one inch of yarn per stitch you plan to cast on, plus a few extra for safety.

How to do it

1. Make a slip knot and place it on your needle. That's your first cast-on stitch.
2. Hold the needle in your right hand. Drape the tail over your left thumb and the working yarn over your left index finger (a "slingshot").
3. Dip the needle tip under the strand on your thumb, then over and through the strand on your index finger, then back down through the thumb loop.
4. Drop the thumb loop off. You now have two stitches on the needle.
5. Repeat until you have the number of stitches the pattern calls for.

Common mistakes

• Pulling too tight. Keep the stitches loose enough to slide along the needle.
• Short tail. If you run out before finishing the cast-on you have to start over — see two ways to never run out below.
• Wrong count. Count your stitches twice. Every pattern assumes you started with the right number.

Short tail? Two ways to never run out

Running out of tail is the classic long-tail cast-on failure, and it has two fixes: measure better, or don't rely on a tail at all.

1. Measure it against the needle. The one-inch-per-stitch rule is a rough guide for worsted weight. For a tail you can trust, wrap the yarn loosely around the needle once per stitch you need to cast on — that wrapped length, plus a hand's width to hold, is your tail. Thicker yarn or bigger needles need more; the wrap accounts for both.
2. Use two strands so the "tail" can't run out. Pull the outside end and the inside end of the same ball (or one end from each of two balls) and tie them together in a slip knot on the needle. Work the long-tail cast-on with one strand over your thumb and the other over your finger — both are attached to the ball, so there is no tail to run short. When you have all your stitches, cut one strand leaving a 6-inch end to weave in, and knit on with the other. The knot counts as a stitch; drop it on the first row if you prefer a cleaner edge.

The knitted cast-on (no long tail needed)

The knitted cast-on builds every stitch from the working yarn, so the only tail you need is the few inches to weave in later. It is exactly one motion — a knit stitch — so it is also the cast-on that teaches you the knit stitch for free.

1. Make a slip knot and put it on the left needle. That's stitch one.
2. Insert the right needle into the slip knot as if to knit (front to back, left to right), wrap the working yarn around the right needle, and pull a new loop through.
3. Don't slide the old stitch off. Instead, put the new loop back onto the left needle, from the front, next to the stitch you knit into. You now have two stitches on the left needle.
4. Knit into the newest stitch (the one nearest the tip) and place that loop on the left needle too. Repeat until you have the number the pattern calls for.

Reach for it when you don't know the final stitch count, when a pattern says "cast on N sts at the beginning of the next row" (adding stitches mid-project, or making a buttonhole), or whenever estimating a tail feels like guesswork. It is a little looser and less elastic than long-tail; its firmer cousin, the cable cast-on, is the same motion but you knit between the last two stitches instead of into the last one.

Ready to cast on? Every free pattern in the pattern library starts with the stitch count you need.

Next: Knit & purl →