Learn how to estimate the yarn requirements for a bind-off the right way.
You are in the last row of your project, but there is only a small amount of yarn left. And now you are wondering just how much yarn you need for a bind-off, right? Time to play yarn chicken? Well, in this tutorial, I’m going to show you how to calculate the yarn requirements for the most popular cast-off techniques.
Now, don’t be scared. You won’t need a degree in higher mathematics to solve the riddle. A tape and a calculator (most mobile phones have one these days) are all you need.
The rest of the work, I already did for you: I knit quite a couple of swatches, measured them, and then marked the starting and endpoint of the bind-off row with a textile marker. Next, I unraveled them and measured the yarn. Then, I divided the total yarn requirements for the bind-off by the total width of the swatch. The result is a simple factor.
You can use this factor to calculate how much yarn you need to leave for your bind-off. Simply measure the width of your project with your tape and multiply it with the factor. Or easier yet, stretch out your project on the needles and then measure out x-times of yarn with your project as a benchmark.
Note: The factor will vary a bit depending on your gauge. I am a fairly tight knitter.
Long tail cast-off yarn requirements
The standard long tail bind-off is not only very popular, it’s also very efficient and only uses a small amount of yarn.
To be on the safe side, you’ll need 5 times as much yarn for the bind-off as your project is wide.
This will leave a little tail of maybe 3-4 inches for weaving in the tails as well. (The exact factor was 4.6 for my swatch. It was 12 cm wide and I needed 56 cm for the cast-off.)
If you don’t have a tape measure at hand and it’s a bit harder to measure your project, you can also wrap the yarn around your project. Lay it on a table and if you can wrap the yarn around 4 times, it should be enough. Why 4? Well, you won’t be able to pull the yarn taught that way. In the picture above, you can see the actual amount of yarn needed for the bind-off. It measured up to 4.6 times the width of the project, but yarn tends to curl a bit.
How much yarn for an I-cord bind-off
I don’t know what it is but recently every shawl pattern I see uses an i-cord bind off. To be fair, it certainly does look lovely, but it’s also quite a bit more complicated to knit. It’s also quite the yarn eater.
For my little swatch (which is 12 cm wide), I needed a whopping 161 cm of yarn to cast off all stitches. If you do the math and round it up a bit for good measure, that means you’ll need around 13 times as much yarn as your work is wide for an i-cord bind-off.
(Yes, the exact factor is 12.6, but you will need a little tail for weaving in anyways).
Note: For very short projects, the factor will be slightly higher due to the fact that you cast on 2 stitches to get started with the i-cord.
How much yarn for a picot bind-off
A picot cast-off is quite the yarn eater as well and fairly similar to an i-cord in terms of yarn requirements. Depending on your repeat (meaning how many standard cast-off stitches you have got between the picots), you will need more or less yarn. In this case, you would have to do your own measuring. I knit my swatch by casting on 2 stitches with a knitted cast-on for every picot and kept 2 stitches between them.
As a result, my swatch of ~12.5 cm needed 193cm of yarn for the picot bind-off. This translates to about 15.5 times as much yarn as your project is wide.
Further things to know
I already mentioned at the very beginning, that these factors work for me, but they might actually differ a bit depending on how loose or tight you knit (so your gauge). It also depends a bit on how tight or loose you bind off (like when you pull out the loops to create a stretchier cast-off for ribbings, etc).
So, I’m afraid my factors are only a rough starting point. Though the looser you knit, the less yarn you will actually need to finish a row, so I’m confident you won’t be too far off the mark. That being said, nothing speaks against doing your own little test. If you tie a little slip knot at the start of your row as a marker, you can just cast on a certain amount of stitches (say 10), carefully unravel that part, and do your own calculation based on your yarn requirements.
That might be a bit tedious, but for a big lace shawl with a couple of hundred stitches, it could pay off.