Estimating Yarn Tail Length by Joyce Jones

Learn Something New Winter 2023–2024

Beginning a new project is exciting. We are anxious to cast on and knit! Most patterns simply say to cast on a certain number of stitches and allow the knitter to determine which cast-on method to use. This allows the knitter to choose the cast on they think will work best for the project.

Cast-on methods can be broadly divided into two categories: those that have a short tail and those that have a long tail. Written instructions for a cast on might say, “Make a slip knot, leaving a short tail.” This implies that the tail should be long enough to be easily secured within the fabric. A good length is 6–8”. Other instructions might say to make a slip knot, leaving a long tail, with no length provided for that tail. That is because the length is directly related to the number of stitches to be cast on, the yarn, and the needle size used. It’s different for each situation.

A pattern may say to cast on using a long tail and leave it up to the knitter to determine what the tail length should be. This article will focus on those cast ons that utilize a “long tail” and offer options for estimating the length of that tail.

Preparing for a Long-Tail Cast On

Long-tail cast ons can be thought of as having two strands: the tail strand and the working yarn strand. The tail strand begins at the cut end and is as long as the knitter determines is needed. At the end of this length, a slip knot can be made which will be placed on the needle. On the other side of the slip knot, the working strand begins and travels to the ball of yarn. The standard long-tail cast on was used while testing different options of estimating the length of the tail.

Figure 1 shows the yarn positioned for the standard long-tail cast on. There is a long tail around the outside of the thumb that will be used to create a rope-like foundation under the needle; the slip knot on the needle, which will count as the first stitch; and the working yarn draped over the index finger, which will create loops on the needle. Both strands are held in the palm of the hand by the remaining fingers.

There are other variations of this method that produce the same effect, and each has its own name, which can be confusing. For example, Montse Stanley, in her book, Knitter’s Handbook, shows five ways to achieve the results of this cast on in a section headed, “Two-strand cast on.” Her German cast on is what is commonly referred to as standard “long tail.”

Ways to Estimate the Long-Tail Length

I combed through many print and electronic sources while doing my research. Some sources direct how to work the cast on but don’t explain the purpose of the long tail or discuss how long it should be. Others offer a way to estimate long tail length, which may or may not take into account the factors of yarn weight or needle size. And no source can factor in the individual tension the knitter uses when casting on. It might not be thought of as a big deal, but even as I practiced and analyzed my cast on and had a friendly group of knitters do the same, I found that we all used varying lengths using the same yarn and needles while casting on the same number of stitches. My length even changed from day to day conducting the same experiment!

I’ve chosen options that have a good semblance of accuracy and offer my pros and cons of each. Let’s take a look at ways to estimate the length of a “long” tail.

OPTION 1: Be Carefree!

If there is an abundance of yarn and no concern about yarn waste, pull out an extremely long length and be done with it. Or if your experience provides an innate sense as to how much length will work for a given number of stitches, just extrapolate that length as needed. In either case, don’t really dwell on it and just let the chips fall where they may. If the tail ends up long, maybe you can plan to use it for seaming. If it’s short, just start over. No big deal.

Pro: Takes little thought and can be quick.
Con: Relies on guesstimation, which may or may not work out.

OPTION 2: Use Two Balls, or the Outer and Inner End of a Center-pull Ball.

This method will always provide a long enough tail. Use the ends of two balls of yarn or both ends of the same ball of yarn. Hold them together and make a slip knot, leaving short tails to easily weave in later (5–7”). The slip knot will not count as a stitch and will be removed from the needle on the next row and undone. This will add a little more length to the tail for weaving. If making a multicolored cast on, this will be the method used. Figure 2 shows two colors tied into a slip knot and the yarn in position for standard long-tail cast on. The thumb yarn will create a contrasting edge below the needle.

Pro: No worries! No measuring or calculating. It works for all yarns and needle sizes.
Con: A single ball must have both ends easily accessible. If using a single ball, the outside strand will twist around the inside strand, and the long tail strand will build up its own twist and end up twisting on itself. The more stitches needed, the more it will twist. Pulling out longer lengths helps to move the twists farther away from the hands. Once the long tail is cut, everything goes back to normal.

OPTION 3: Wrap. Unwrap and Cast on 10 Stitches. Unravel. Duplicate Length

This method is very accurate but takes more steps than other methods. It determines how much yarn length is needed for 10 stitches, and the length is duplicated until the target number of stitches has been reached.

1. Divide the total number of stitches needed by 10 to determine the number of lengths. Example: For 126 cast-on stitches, 126/10 = 12.6 lengths needed.
2. With the end held firmly against the project needle, wrap the yarn around the needle 10 times to represent 10 stitches. Wrapping the yarn at an angle and leaving some space between wraps provides a cushion against coming up short on length. See Figure 3. If using a circular needle with a shorter shaft, you can push some wraps toward your fingers in order to be able to wrap 10 times.
3. Pinch the yarn at the end of the final wrap and unwrap.
4. Add about 6” to this length and make a slip knot at that spot.
5. Place the slip knot on the needle and cast on 10 stitches with this length, making sure the yarn tail is over the thumb. There should be 10 stitches PLUS a slip knot on the needle.
6. Use the tail strand to make another slip knot close to where it comes out of the last cast-on stitch. To do this, use the tail strand and make a loop about 2” away from the tip of the needle. Place the part of the strand that is between the loop and the needle through the loop. This will allow the knot to cinch up close to the needle. Do not place the loop on the needle. Figure 4 shows the slipknot, the 10 cast-on stitches, and the extra slip knot after the final cast-on stitch.
7. Slide the stitches off the needle and, while pinching a slip knot in each hand, carefully extend the hands so the stitches unravel. The yarn between the slip knots is the length you will need for every 10 stitches of your cast on. See Figure 5.

From here, there are three ways to duplicate the length:

1. Calculate It. Measure the length between the slip knots. Multiply the result by the number of total lengths needed plus an additional 10” for insurance and to be able to weave in the end.
   Example: Number of total lengths needed is 12.6. The measured length between the slip knots is 8”. 12.6 lengths x 8” = 100.8” needed. Round up to 101” + 10” extra for insurance. Measure out 111” for the tail.

Pro: Very accurate. It works for all yarns and needle sizes.
Con: Calculations are necessary. A measuring device and calculator are used.

2. Zigzag. Lay the yarn on a flat surface and zigzag the yarn back and forth in lengths equaling the length between the slip knots. Continue for as many times as needed. Add 10” to the final length for insurance. Figure 6 shows this method with 6 zigzags for 60 stitches.

Pro: Very accurate. No math involved. Works for all yarns and needle sizes. You can double the initial length to represent 20 sts to reduce the number of lengths needed.
Con: Must have a flat surface to work on.

3. Walk It Off. When making the final slip knot near the last cast-on stitch, make it large enough to fit your index finder. Place the loop on the left index finger and carefully remove the stitches while leaving the original slip knot on the needle which is in your left hand. Working hand over hand, walk off the lengths as needed. Add 10” to the final length for insurance. Figure 7 shows six walked off lengths for 60 stitches. This video demonstrates walking off the yarn lengths using the loop on the index finger and the needle as helpers.

Pro: Very accurate. No math involved. It works for all yarns and needle sizes. If the yarn gets away from you when walking off the lengths, you still have the slip knots that delineate the original length so it’s easy to start again.
Con: Walking off many lengths can get unwieldy.

OPTION 4: Cast On 10 sts. Unravel. Duplicate Length

This is a variation of Option 3 with the “wrap and unwrap” steps eliminated.

1. Divide the target number of stitches by 10 to determine the lengths you will need to duplicate.
2. Pull out a length of tail that you are confident will give you 10 stitches and make a slip knot. Don’t try to pull out too much because it may get in the way later. Place the slip knot on the needle. Do not count it as a stitch.
3. Cast on 10 stitches with this length, making sure the yarn tail is over the thumb. There should be 10 stitches PLUS a slip knot on the needle.
4. Use the tail strand to make another slip knot close to where it comes out of the last cast-on stitch. To do this, use the tail strand and make a loop about 2” away from the tip of the needle. Place the part of the strand that is between the loop and the needle through the loop. This will allow the knot to cinch close to the needle. Do not place the loop on the needle (see Figure 4).
5. Slide the stitches off the needle and, while pinching a slip knot in each hand, carefully extend the hands so the stitches unravel. The yarn between the slip knots is the length you will need for every 10 stitches of your cast on (see Figure 5).
6. Use any of the three ways to duplicate the length that are offered in Option 3 above.

Pro: Very accurate as long as the duplicated lengths are the same. It works for any yarn and needle size. No calculations are needed if using the zigzag or walk-off method.
Con: Calculations are necessary if using the measured length option. A flat surface is needed for zigzagging. Walking off many lengths can get unwieldy. Any extra length of the tail from casting on the 10 stitches might get in the way.

OPTION 5: Wrap 10 Times

This is also a variation of Option 3 and eliminates casting on the 10 stitches. It is a good short-cut method if you are confident the wrapped length will be enough for 10 stitches.

1. Divide the target number of stitches by 10 to determine the number of lengths needed.
2. Make a slip knot close to the end of the yarn.
3. Hold the slip knot against the shaft of the needle and wrap the yarn around it 10 times to represent 10 stitches (see Figure 4).
4. Make another slip knot at this point and unwrap.
5. Use any of the three ways to duplicate the length that are offered in Option 3 above.
   If using a cast-on method that twists the strands under the stitches (such as Twisted German), add an additional 10%.

Pro: Very accurate, as long as you are confident that your wraps will cast on 10 stitches. It works for any yarn and needle size. It’s quicker than actually casting on 10 stitches and unraveling. No math needed unless you to measure the length and calculate.
Con: You must be confident of your wrapped length. Calculations are necessary if using the measured length option. A flat surface is needed for zigzagging. Walking off many lengths can get unwieldy. Additional length of 10% needs to be added if using a twisted cast on.

OPTION 6: Measure 3 to 4 Times the Desired Width

Many sources and teachers recommend using a tail that is between 3 and 4 times the width of your desired fabric because it’s easy to remember and execute. Some say to add additional length to be able to weave in the end, while others do not.

Differences in individual tension play a part in the accuracy of this method. I found I was beginning to worry that I might run out when using 3 times the width. I found it best to use 3.5 times the width with all but the lace weight yarns, which worked fine with 3 times the width. I was sure to add about 10” extra for insurance. You might want to experiment until you get the feel for what works for you.

Pro: Is fairly reliable. Minor calculations are involved. No preliminary actions are necessary as in other methods.
Co: The width of the fabric desired needs to be known. This might mean finding the info within a pattern (Finished Measurements or a schematic) or running some calculations to figure it out yourself. To do this, take the total number of stitches and divide them by the stitch gauge of the desired fabric. This will tell you the width. Example: 126 stitches/5 stitches per inch = 25.2” wide. An additional length of 10% needs to be added if using a twisted cast on.

OPTION 7: Wrap for All Stitches Needed

Wrap the yarn around the needle for the number of stitches needed. Unwrap and add an additional 10” for insurance. This method is best used with a relatively small number of stitches because it is easy to lose count of the wraps. After the shaft is full of wraps, push them down the shaft to have room for the next set of wraps.

Pro: No math involved. It’s good for what you deem a manageable number of wraps.
Con: Not good for a large number of stitches for a number of reasons. It can be hard to keep track of wraps. A shorter needle shaft minimizes the number of wraps that can be made. And the yarn tends to untwist as it is wrapped, which can result in a sloppy-looking yarn tail. Using a circular needle means the wraps go down on the cable. They can lengthen out and reduce in size which makes removing them frustrating. An additional length of 10% needs to be added if using a twisted cast on.

Running Out of Tail!

What happens if you’ve done your best and you still end up running out of yarn tail? Do you have to begin all over again? No. You can add another length right where you are.

1. Determine which side of the cast on will be the right side.
2. Leave a length of your existing tail long enough to weave in later and have your last stitch a little loose so there is space under the needle between it and the penultimate stitch.
3. Use another length of yarn and thread the cut end right side to wrong side through the space between the last two stitches until there is about 6” on the wrong side.
4. Snug up the last cast on stitch by tugging on the old tail and the working yarn.
5. Hold both short tails on the wrong side against the needle as you continue to cast on with the new tail. If the bumpy side of the cast on is considered the wrong side, it will be necessary to take the old tail to the left of the working yarn and under the needle to the wrong side. Weave in the short tails later.

Figure 8 shows the new tail threaded front to back between the last two stitches with the new short tail on the bumpy (wrong) side and the new long tail on the smooth (right) side of the cast on. Figure 9 shows some new stitches cast on with the new tail. Both short tails are on the wrong side.

Are there other options? Well, if you really are in a pinch, yes. You can turn the work around and use the purl version of either the cable cast on or the knit cast on for the remaining stitches. I find they best resemble the long tail and will do the trick in an emergency. Take care that all cast-on stitches have the same elasticity.

Some sources say to trade the working yarn with the long tail to eke out more stitches. My testing found it typically takes more yarn to form the loops on the needle. Trading out the strands means the tail would be used up even sooner. For this reason, I avoid that trick.

Casting on is just the beginning of a wonderful time of knitting. Having a successful start will get the project off on a happy note. Experiment to find out your favorite way to be sure your long tail makes it to the very end.

Bibliography

Bestor, Leslie Ann. Cast On, Bind Off: 54 Step-by-Step Methods. Storey, 2012.

Buss, Katharina. Big Book of Knitting. Sterling Publishing Co., Inc., 1999.

Hiatt, June Hemmons, and Jesse Hiatt. The Principles of Knitting. Touchstone, 2012.

Lyons, Patty. Knitting Bag of Tricks. David & Charles, 2022.

Sease, Catherine. Cast On, Bind Off. Martingale, 2012.

Stanley, Montse. Knitter’s Handbook. Reader’s Digest, 1993.

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