The long-tail cast on is one of those knitting “gateway skills” that shows up everywhere: hats, sweaters, socks, scarves, you name it. It looks tidy, it is nicely stretchy for most projects, and once your hands learn the motion, it feels almost meditative.
It also has two classic beginner frustrations:
- You run out of tail before you finish casting on.
- Your edge is so tight you could bounce a quarter off it.
Let’s fix both, step by step, with a few teacherly tricks I wish I could have taped to my needles back in college finals week.
What it is
Long-tail cast on is a two-strand cast on. One strand comes from the working yarn attached to the ball, and the other strand is the “tail” you measured out before you began.
Those two strands work together to create:
- Cast-on stitches sitting on your needle
- A neat bottom edge that looks like a row of little “bumps”
This is why tail length matters. You are literally using the tail to build part of every stitch.
Before you start
Needle choice
Use the needle size called for by your pattern. If you tend to cast on tightly (many of us do), you have three friendly options:
- Use a larger needle just for the cast on (often 1 to 2 sizes up), then switch back on Row 1.
- Cast on over two needles held together, then slide one out before knitting the first row.
- Consciously keep a tiny “gap” between stitches as you form them (more on this below).
Slipknot or no slipknot?
Most tutorials start with a slipknot, and that is totally fine. If you dislike the look of that first knot, you can use a non-slipknot start, but for most beginners, a slipknot is the easiest and most reliable way to begin.
Where to hold the yarn
This cast on uses the “slingshot” position:
- The tail goes around your thumb.
- The working yarn (from the ball) goes around your index finger.
A quick memory trick: the tail is usually the strand closer to the needle tip when you begin, and the working yarn travels back to the ball.
Tail length
Running out of tail at stitch 97 of 100 is a very specific kind of heartbreak. Here are dependable ways to estimate tail length, from simplest to most exact.
Method 1: Quick estimate
For many worsted-weight projects, a commonly used rough starting point is:
- About 1 inch (2.5 cm) of tail per stitch, plus an extra 6 to 10 inches (15 to 25 cm) for weaving in.
Consider this a comfortingly fuzzy estimate. Needle size, yarn thickness, and how tightly you cast on can change the number a lot.
Method 2: Needle wraps (best for beginners)
This is simple and usually very accurate because it uses your actual needle size and yarn thickness.
Take your yarn tail and wrap it around your needle the same number of times as stitches you need to cast on.
Add a buffer: wrap a few extra times (or add about 10 to 20 percent more wraps), especially if you cast on tightly.
Pinch the wraps so they do not unravel and slide them off.
Add 6 to 10 inches (15 to 25 cm) for weaving in and a little breathing room.
Now you have a tail that is much less likely to betray you. No math required, which is exactly how I like my crafting.
Method 3: Test count and measure
If you want precision for thin yarn or a large stitch count:
Measure out a tail you know is long enough, then cast on 20 stitches.
Measure how much tail you used for those 20 stitches.
Multiply that amount by your total stitch count, then add 6 to 10 inches (15 to 25 cm).
This is extra, but sometimes extra is soothing. Fiber arts are allowed to be soothing.
If you do run out of tail: You can start over, or you can switch to a different cast on (like knitted cast on) for the remaining stitches. It will look a bit different, but if it is for an inside seam or a hidden edge, it can be a perfectly reasonable “no one will know but me” fix.
Step by step
I’m going to describe the classic slingshot long-tail cast on. Read through once, then try it slowly. Speed comes later, I promise.
1) Tail and slipknot
Measure your tail using one of the methods above. Make a slipknot and place it on your needle, then snug it gently.
Whether that slipknot “counts” as a stitch depends on the pattern and designer. A practical way to handle it:
- If your pattern says CO 100 sts, many knitters count the slipknot as 1 stitch, then make 99 more cast-on stitches.
- If your pattern says do not count the slipknot (or you know you prefer not to), make the slipknot, then cast on the full number of stitches after it.
When in doubt, follow the pattern’s wording. It is the boss of the project.
2) Slingshot position
Hold the needle in your right hand. With your left hand:
- Tail over your thumb
- Working yarn over your index finger
- The two strands cross in your palm
It should look like a little triangle of yarn between your thumb, index finger, and the needle tip.
3) Down, up, through, tighten
Each new stitch follows the same pathway:
Go down into the thumb loop from front to back with the needle tip.
Go up and over the index-finger strand (catch that strand on your needle).
Bring the needle back through the thumb loop, pulling that index-finger strand with it.
Drop the thumb loop off your thumb.
Tighten gently by pulling on the tail and working yarn just enough to snug the stitch onto the needle.
Repeat until you have the required number of stitches.
Beginner checkpoint: Your cast-on stitches should slide along the needle without a fight. If you have to shove them, the edge is too tight.
Avoid a tight edge
If you have ever knit a beautiful hat only to discover the brim fits like a headband made of regret, you are not alone. Long-tail cast on can get tight if you snug each stitch too firmly.
Use “snug,” not “cinch”
After you form each stitch, tighten until the stitch touches the needle. Then stop. If you keep pulling past that point, the yarn tightens around the needle and robs your edge of stretch.
Try a larger needle
Cast on with a needle one or two sizes larger than your pattern needle, then switch back for Row 1. This keeps the loops of the cast-on edge roomier, which usually means a stretchier edge.
Cast on over two needles
Hold two needles together as one while casting on. When finished, slide one needle out. The stitches will be slightly larger and more forgiving.
Mind the edge strand
Long-tail creates two visible strands: the lower edge strand (mostly the tail) and the upper strand that becomes the tops of your stitches (mostly the working yarn). If you tug hard on only one strand, you can accidentally tighten the whole structure.
Instead, snug the new stitch by pulling both strands evenly, then relax your grip before you make the next stitch.
When you need more stretch
For very stretchy edges (like the top of toe-up socks or an extra-elastic hat brim), you may prefer a cast on designed for more stretch, such as a German twisted cast on.
If you want a very polished, elastic edge that pairs especially well with 1x1 rib, an Italian tubular cast on is gorgeous, but it is more advanced and a bit fussier. Long-tail is wonderfully versatile, but it is not the stretchiest option out there.
Common problems
Row 1 is hard to knit
This usually means the cast on is too tight, or the stitches are twisted around the needle.
- Fix: Use a larger needle for the cast on, and make sure you are not yanking each new stitch tight.
- Check: The legs of the stitch should sit on the needle like normal knit stitches, not crossed.
The edge looks uneven
Uneven tension is incredibly common at first, especially if you alternate between tightening with the tail and the working yarn.
- Fix: After forming each stitch, snug by pulling both strands lightly (tail and working yarn), then relax your grip before making the next stitch.
- Tip: Cast on slowly for the first 20 stitches. Your hands often “find” the rhythm after that.
I have one extra stitch
This often happens when the slipknot is counted differently than you expected.
- Fix: Check your pattern’s wording. Some patterns count the slipknot as a stitch, and some do not.
- Habit: After casting on, count your stitches calmly (I say this as someone who has recounted the same 84 stitches five times).
I ran out of tail
We have all been there.
- Best fix: Start over and measure again using the wraps method, with a few extra wraps as a buffer.
- Workaround: If you are only short a couple stitches and the edge will be hidden, you can switch to knitted cast on for the last few stitches and keep going.
The tail is comically long
Congratulations, you overestimated like a true maker. That is better than underestimating.
- Fix: Leave enough tail to weave in securely (usually at least 6 inches), then trim the rest after you have woven in.
Count and read it
Long-tail cast on creates a neat edge that is handy to “read” when you are checking your work.
- On the needle: You should see tidy V-shaped stitches like any other row of knitting.
- Along the bottom: You will see a row of bumps or little horizontal bars.
Twist check: All the stitches should face the same direction on the needle, with the front legs lined up neatly along the front edge of the needle. If some stitches flip or cross, the first row can feel weird and look messy. It is worth redoing early.
If your stitches on the needle look crossed or twisted, stop early and redo. Fixing twisted cast-on stitches later is like trying to untangle a necklace chain that has lived at the bottom of a purse for six months. Possible, but not a vibe.
Best uses
This cast on is a reliable all-rounder. I reach for it when I want a clean edge that is moderately stretchy and not too fussy.
- Sweater hems and cuffs (especially if followed by ribbing)
- Hat brims (if you are not needing maximum stretch)
- Scarves and cowls
- Blankets (the tidy edge is lovely for borders)
- Most flat projects that begin at the bottom edge
If your project needs a very firm edge (like some button bands) you may choose something less stretchy. If your project needs a super stretchy edge, choose a stretchier cast on. But for everyday knitting, long-tail is a classic for a reason.
Join in the round
Yes, you can use long-tail cast on for knitting in the round. The two things to watch are twists and that annoying first-join gap.
- Check for twists: Before you join, spread your cast-on stitches around the needle and make sure the bottom edge bumps all face the same direction, like a neat little belt around the needle.
- Close the gap: Snug your first stitch firmly (not violently) after joining. If you often get a hole, cast on 1 extra stitch, join, then pass the first stitch over the extra stitch to reduce the gap and get back to your correct stitch count.
Practice plan
If long-tail cast on feels awkward, your hands just need repetition in a low-stakes setting.
Grab smooth, light-colored yarn (worsted is perfect) and needles around US 7 to 9 (4.5 to 5.5 mm).
Cast on 20 stitches, focusing only on consistent snugness.
Knit one row, then bind off.
Do it again, but cast on with a needle one size larger and compare how the edge feels.
Keep the best little swatch as a reference. I keep mine stuffed in a notion pouch like a tiny yarny security blanket.
FAQ
Is long-tail cast on the same as backward loop?
No. Backward loop cast on uses only the working yarn and is quick but can be loose and uneven for beginners. Long-tail uses both the tail and working yarn, creating a sturdier, more uniform edge.
Do I need a special cast on for ribbing?
You can absolutely use long-tail cast on for ribbing. If you want extra stretch, consider going up a needle size for the cast on, or choose a stretchier cast on method depending on the pattern.
Why does my cast-on edge flare?
Flaring often happens when the cast on is much looser than the fabric that follows. Try casting on with the correct needle size (not bigger), focus on snugging each stitch to the needle, and check that your first row tension matches your usual knitting tension.
Can I use long-tail cast on in the round?
Yes. Cast on as usual, then join in the round carefully, making sure the stitches are not twisted around the needle.
Pep talk
Long-tail cast on is one of those techniques that can feel clumsy until, suddenly, it does not. If your first attempts look a little lumpy, welcome to the club. Every neat edge you admire was once someone’s slightly chaotic practice cast on.
Take it slow, measure your tail with confidence, and remember: your yarn stash is not judging you. Mine is, but only because it wants to be knit into everything at once.
