Yarn Substitution

Substituting yarn

The question comes up every so often at the knitting meet-up and in the Ravelry forums. It takes the form of “Can I use this yarn instead of that yarn?” and any of a number of variations. And the answer is almost always: “It depends.”

Oh, we want this answer to be a simple “Yes”. But it seldom is. Usually the knitter has a valid reason for wanting to use a different yarn than what was used in the printed pattern: Lack of availability, wanting/needing a different colorway, dislike of the particular yarn, etc. If the knitter happens to select a yarn of similar weight and make-up, the substitution will probably go reasonably well – providing, of course, that the knitter can achieve the stated pattern gauge with the chosen yarn. This is the happiest of all occurrences – the yarn you want to use works out well with the pattern and you can just relax and knit happily on your project.

The subject of matching gauge could constitute the contents of an entire article, if not a book. For the sake of brevity, I will simply state that gauge is essential and that any knitter who wishes to produce a well-fitting garment needs to pay attention to gauge – IF she is following a pattern that contains the concept of “fit” as part of the design. (Gauge is less important with scarves & shawls).

Lindy’s Advice #1: When substituting yarns, it is best to select a yarn that is of the same weight and has the same characteristics as the original yarn. But do a gauge swatch to make certain you do not need to make adjustments so that the garment fits correctly.

Perhaps the most frustrating of experiences with yarn substitution is the situation where you have selected a yarn of similar weight and characteristics – but try as you may, you cannot achieve the stated gauge. The advice is usually to go up a needle size or two if your gauge has more stitches and to go down needle sizes if your gauge has fewer stitches. If this works, then wonderful! Proceed with the project. But if, in spite of the change in needle sizes, you still cannot get the stated gauge – well, this can be a significant problem. Being off a half a stitch doesn’t seem like much, but when multiplied over a large number of stitches (say 100 or more), it becomes quite significant and the result is a garment that doesn’t fit properly. You have two options in this situation: 1) try a different yarn (yep, try another one) ; or 2) get out your calculator and start calculating the adjustments needed to ensure a proper fit.

Note: If math makes you anxious and you would never consider recalculating the number of stitches you need to make the garment using your yarn and your gauge – then skip this next part.

Here are the basic calculations you’ll need to make the appropriate adjustments:

Pattern Gauge states “20 stitches and 20 rows = 4 inches” (5 stitches/inch and 5 rows/inch)

To adjust pattern width (i.e. your stitch gauge is different):
Your stitch gauge is 22 stitches = 4 inches. Which is 5.5 stitches per inch

Pattern instructions state that the back of the garment measures 25 inches at the bottom and says to cast on 125 stitches. To adjust for your gauge, you would need to cast on 25 X 5.5 = 137.5 stitches – you will need to round down to 137 stitches so that you have an odd number of stitches, since the pattern has an odd number.
You will need to make similar calculations for width measurements throughout your pattern – it is best if you go through and do this before you starting knitting.

Adjusting pattern length may or may not require some math. If the pattern has instructions that use length (inches) rather than rows, it really isn’t necessary to calculate the number of rows required with your gauge, because you can simply knit to the desired number of inches.

However, if the pattern contains instructions such as “knit 40 rows then begin shaping” – you may want to calculate the adjustments needed, as follows:

Your row gauge is 30 rows = 4 inches – which is 7.5 rows per inch

Pattern row gauge is 20 rows = 4 inches (5 rows per inch)
To calculate the number of rows you need to knit to be equal to the 40 rows called for in the pattern :
40 rows ÷ 5 rows/inch = 8 inches
8 inches X 7.5 rows/inch = 60 rows – so instead of knitting 40 rows then begin shaping, you would knit 60 rows.

A shortcut in these calculations would be to go through and calculate the number of inches that need to be knit using the row gauge of the pattern and then just knitting to the calculated length.

This can be a daunting bit of calculation – but it will result in a better fitting garment with your desired choice of yarn and is thus, worth the effort.

So far, I have discussed what considerations are needed when substituting a yarn of similar weight and characteristics with another. Now about substituting an entirely different weight of yarn…

I have attempted this several times and have not been happy with the result each time. Hence, Lindy’s Advice #2: No matter how much you love the yarn you want to substitute and the pattern, if the yarn is not the same weight and/or does not have the same characteristics as the yarn used in the pattern – DO NOT use that yarn with that pattern.

I know, I know – you really want to use this yarn, but it’s like trying to fit a square peg in a round hole. I feel your pain, I really do. But don’t do it, you won’t be happy with the result.

I think every knitter has tried using bulky yarn for a worsted weight pattern or visa versa. The results have probably been disappointing and the garment was either too big or too small. It certainly was for me.

I know of many knitters who have attempted to double-strand worsted weight or sport weight yarn to substitute for bulky weight. It can be done with some success, but once again – you have to do a gauge swatch and make the necessary adjustments for differences between your gauge and the pattern gauge. You just can’t get away from the math…

But wait! There is a way to substitute yarn so that it doesn’t drive you crazy: “Free yourself from the pattern”.

Huh? What do I mean by that? Well, as a knitter you will eventually reach a point in your knitting experience when you begin to understand the basics of garment design and construction. Granted there are literally hundreds of thousands of written sweater patterns available. But any sweater has a front, a back, two sleeves and a neck. If you understand how to construct the basic parts and match them to your desired body measurements – you really don’t need a specific written pattern.

Let’s start with that pattern you want to knit with a different weight of yarn. What are the characteristics of the garment? How are the sleeves shaped? How is the front shaped and how is the back shaped? What do you like about this pattern?

Does the pattern use a textured stitch patterning or does it have a particular colorwork patterning? Are there charts for the stitch pattern(s) or the colorwork pattern(s)? You can use these to make your own customized sweater with your chosen yarn.

How? Well, it will require some thinking, some planning, some math (sorry!) and a very good set of body measurements. Armed with the knowledge of sweater design – you can go from carefully following a written pattern to using the pattern as an inspiration for your own custom designed sweater.

I will outline how to do this in my next post. Off to find my sweater design references…

1 thought on “Yarn Substitution”

  1. This is really helpful.

    Maybe in the sweater design part you could answer questions about sizing? What if your pattern doesn’t have your size?

Comments are closed.

Related Post

A Study of Pooling in a Variegated Sock YarnA Study of Pooling in a Variegated Sock Yarn


Several days ago, I decided to knit a pair of plain vanilla socks using Serenity Sock Weight Yarn (Premier Yarns) in the colorway Amethyst. This was a yarn I had purchased at my local Hobby Lobby and had been sitting in my sock yarn stash for a few months. In the skein, the yarn appears to be a mix of greys and purples, and I thought it would result in a striping of the socks. The label does not indicate that the yarn is “self-striping”, but the picture on the label shows a sock with an interesting variation of stripes.

Since I had never knit with this yarn, I knit a circular swatch to determine needle size and gauge before starting on my socks – and this is where my study in “Pooling” began. I started with US 2 (2.75 mm) needles and cast on 64 stitches (which is what I would use for my socks with a gauge of 7 stitches per inch). As I worked on the swatch, I noticed that the yarn was not knitting up in the stripes the way I had anticipated – in fact, it seemed to be predominately purple on one side of the swatch and predominately grey on the other side.


Obviously, I had some “pooling “ going on. Pooling is an effect that occurs when a variegated yarn knits up in “pools” of color, rather than in stripes. Now, I wasn’t really sure I liked the effect – and my stitch gauge was 6.25 spi, rather than the 7 spi I wanted.

So, I decided to do a second swatch with fewer stitches, a smaller needle – and because I had read about pooling in a Rav thread, I also decided to knit from the outside of the skein instead of the inside. I cast on 52 stitches on size US 1.5 (2.50 mm) needles and knit away – and I got more striping – not even stripes, but definitely stripes on both sides of the swatch.


So, I took a picture of the two swatches and posted a comment on Ravlery under the thread, “Examples of Pooling Good & Bad”, stating what I had observed along with my assumption that the change was probably due to knitting from the outside of the skein – and completely ignoring the fact that I had changed the number of stitches in the swatch and this might also be contributing to the way the colors were knitting up.

I must admit, I did not anticipate much of a response to my comment in this thread. But I received several. It’s one of the things I love about Ravelry – fellow knitters are always willing to share and question things. Anyway – after reading the comments, I decided I needed to do a little more work before I could actually answer my fellow Ravelers’ questions.

Off I went to swatch again – this time I decided to start from the inside of the skein, use US 2 (2.75 mm) needles and begin by casting on 72 stitches. I knit approximately 1.5 inches, then purled and decreased the number of stitches to 64 stitches, knit another 1.5 inches, purled and decreased to 54 stitches and knit another 1.5 inches. Here’s a picture showing how the yarn pooled with different numbers of stitches.

So – in response to Robocass and Hypercycloid, who asked me if the difference might be due more to the difference in the number of stitches in my swatches: Clearly, the number of stitches used results in very different color patterning and it doesn’t really matter whether I knit from the inside or the outside of the skein.

Hypercycloid also asked about the length of each of the colors in the yarn. Hmm – I hadn’t thought about that, so I got out the measuring tape and discovered that each purple section of the yarn was approximately 19 inches, while the grey sections were approximately 12 inches. Not quite, but almost a 3 to 2 ratio. Statnerd suggested I count the number of grey stitches compared to the purple stitches in my wider swatch – I did and ended up with 27 stitches of grey to 37 stitches of purple. Again, this is close to a 3 to 2 ratio of purple to grey. All of you were correct in your observations that the colors shift around the circumference of the swatches – and due to the differences in the number of stitches, the colors stack up very differently for different numbers of stitches.

Zgma commented:

“It doesn’t look like a self-striping yarn to me. The striping you got in the top sample is a result of the colors pooling in a way that looks like stripes, not actual “self-striping”. When yarns are labeled self-striping, it is because the runs of color are large enough that for the project intended (as in, socks for self-striping sock yarn), the color will last for all the stitches in at least one round or row, usually more. When a particular color (for instance, the black in your sock samples) lasts for part of a row, but then in the next row the color occurs before or after it did in the previous row in such a manner that it looks like striping, it doesn’t mean that the yarn is self-striping – just that it is prone to pooling in a stripey way.”

Yep, you are right about that.

To each of those that took the time to comment — thanks! I learned a great deal about pooling and variegated yarns.

I did a little internet surfing on the subject, as well. I found two informative posts about Pooling — One from the Yarn Harlot and the other from Knitting Sutra.

So – I am not really sure if I like this particular yarn – but I have decided to proceed with using it to knit a pair of plain vanilla socks. I am going to use US 2 (2.75 mm) needles with a gauge of 6.25 spi and cast on 54 stitches (this should fit my foot). I’ll post pictures of the final result.

How to Knit a Helpful Swatch – Part 2 Stitch PatternsHow to Knit a Helpful Swatch – Part 2 Stitch Patterns

In my previous post, I discussed how to make a preliminary swatch to select the size needle that gives you a fabric that you like and then how to knit a gauge swatch. The gauge swatch is measured to give you your stitch gauge (stiches per inch) and your row gauge (rows per inch).

At this point, you might think you are ready to cast on and begin knitting your sweater – BUT….

Are you planning on using some type of ribbing for the bottom, cuffs and neckline of the garment? Are you planning on using a certain textured stitch pattern, a lace pattern or cables in your sweater? Will you be combining two or more stitch patterns in the body of the sweater? If the answer to any of these questions is “yes”, then you need to do more swatching.

Swatches with Borders: Have you ever knit something with a definite edge made by knitting either garter stitch or seed stitch and then found that the edges curl? The reason this happens is usually due to a difference in gauge between the stitch pattern used for the border and the stitch pattern used for the body. Thus, if you are knitting piece with a border that is different than the body of the piece, knitting a swatch with the borders on it provides you with an opportunity to make adjustments to minimize or eliminate the problem.  Suzanne Bryan has a nice video on this that you may find helpful, here’s the link:

Short Rows in Garter or Seed Stitch Border

Note: I don’t recommend using garter stitch borders on gauge swatches even though others do. The border tends to distort the swatch and may affect the accuracy of your measurements.

Swatches of Ribbing: Ribbing by nature tends to “pull in”. Which means that 30 stitches of ribbing will have a smaller width than 30 stitches of stockinette stitch. How much of a difference can be quite significant and affect the way the garment fits around the hips and neck as well as around the wrists on a long sleeve. Also, some knitters find that their ribbing stitches appear larger than their stockinette stitches due to changes in tension. One solution for this is to use a smaller needle when ribbing – but if you do that you may need to have more stitches to get the right width of fabric for a proper fit. Knitting a swatch with your selected ribbing pattern followed by a transition to the stitch being used for the body of the sweater will provide you with the information you need to decide what you want to do. You might want to knit separate swatches with different ribbing patterns to select which ribbing you prefer to use in your garment. (You don’t have to use the same ribbing that the designer did for the pattern if you don’t want to…just saying.)

Swatches of Stitch Patterns:

In this post, stitch patterns refer to textured pattern stitches, lace patterns, cable patterns, etc. Basically any grouping of stitches that combine to make a pattern from the variations in stitches used.

I think making a swatch of the stitch patterns used in a written pattern provides a great deal of useful information about how the finished garment will look and feel – and fit! It’s also good practice before doing it as part of your finished item.

Keep in mind that most written patterns only give gauge in stockinette stitch and while that tells you what the designer’s gauge is – it does not tell you how the gauge changes in the stitch pattern(s) used in knitting the garment. If you find a written pattern that states the gauge of the stitch pattern – great. But does your gauge match that? Swatching is the only way you will know.

If you are only using one stitch pattern, then knitting a swatch with two or more pattern repeats will help you figure out how the pattern affects the width and length of the garment and what adjustment you might need to make to obtain the correct size of garment you want. If you combine it with your ribbing, you will see how the ribbing affects the transition to the main fabric of the garment.

If you are combining more than one stitch pattern within the main fabric of a garment, I recommend doing individual swatches for each stitch pattern to use as a gauge swatches.

Then to see what happens when the stitch patterns are combined,  you should do a swatch large enough to include all of the stitch patterns used in the order you plan to use them. This may end up being a very large swatch – even enough stitches for the back of your garment. This type of swatch will provide you with a lot of helpful information and give you insight into what adjustments you might need to make for a great fitting garment.  More on this in a later post.

Knitting Needle Sizes & ConfusionKnitting Needle Sizes & Confusion

Knitting Needles sizes are fairly straightforward in the sizes that one uses for DK, worsted weight and bulky yarns. (Size US 4 and up). But it is a much different story when it comes to small diameter needles used to knit fingering, lace and other finer weight yarns. This can be very confusing – I just discovered that there is a significant variation in the sizing labels for some of these needles.

Let’s start with the standard “US” sizing – which uses a numerical designation for knitting needles, from “0000” up to 35 – with the needle diameter increasing as the numerical designation increases. Seems like a fairly straightforward system – until you run across US size 1 & 2 needles that are different diameters. If you never use a knitting needle smaller than US size 4 (which has a diameter of 3.5 mm), this will not be a problem for you. IF, however, you get into knitting socks and lace using much smaller diameter needles – it may cause you to pull out your hair.

Fortunately, most knitting needles sold today also come with their diameter size stated as well as their US size. What I have currently in my assortment of circular knitting needles are as follows: US Size 0 (2.00 mm); US Size 1 (2.25 mm), US Size 1 (2.50 mm), US Size 2 (2.75 mm), US Size 2 (3.00 mm). These needles have all been purchased in the last 10 years. I have seen patterns referencing size 1.5 needles, so I am guessing that the size 2 (2.75 mm) needle may also be a 1.5, but it’s difficult to tell for certain. Just a word of caution to those using patterns calling for these US sizes of needles – make certain your metric diameter matches the pattern (if it’s stated) and BE SURE to check your gauge!

I found two websites that have charts comparing the US sizing to the metric diameter:
http://www.fibergypsy.com/common/needles.shtml
http://www.lionbrand.com/cgi-bin/faq-search.cgi?store=/stores/eyarn&faqKey=97

Point to remember: Gauge is the measurement of the number of stitches per inch you get with a particular needle – this is more important than using the size of needle stated in a pattern. Always do a swatch for gauge!