There are many reasons why you might want to substitute your yarn in a knitting or crocheting project. Perhaps you want to use a more durable fiber or want to make a fabric that’s more breathable. Perhaps you want to make the project go faster by using a chunkier yarn.
But how exactly does yarn substitution work? If you are using a yarn with the same weight, you will still have to calculate how much yarn is needed for your project and how the new fiber will affect the final look of your garment. If you are using a different weight yarn, then even more calculations need to be done to make sure that your final garment will turn out exactly how you want.
In this article, let’s explore some guiding principles to help you find the best yarn substitution for your project.
Considerations When Substituting Yarn
Why do you want to use a different type of yarn than the pattern’s recommendation? The answer to this question will help you pick out a substitution in the correct yarn weight and fiber. Let’s take a look at some considerations.
Size Of Final Garment
The first aspect that substituting yarn can affect is the size of the final garment. Every pattern will have measurements that indicate how big the final garment will be.
If you use a thinner yarn than the pattern’s recommendation (accompanied with smaller knitting needles or crochet hook), the final garment will be smaller than the pattern’s measurements.
On the other hand, if you use a chunkier yarn (with bigger needles or crochet hook), then the final garment will be a bit larger than the pattern’s indication.
Of course, this doesn’t matter so much if you are making a chunky sweater, an afghan, or a blanket. However, if you want the size of the final garment to be the same as in the pattern, you’ll have to use the same yarn weight and needle/hook size as the pattern’s recommendation.
With a substitute yarn, you’ll also need to pay attention to the gauge as it can affect the size of the final garment.
Substituting yarn can also affect the look of the final fabric, particularly how much drape it will have or how sturdy and chunky it is.
If you want the final fabric to be drapy, then using a lighter yarn with the same needle or hook size as the pattern’s recommendation will produce a lacy fabric that drapes very well. Substituting fibers like silk or mohair can also produce a drape in the final fabric.
On the other hand, if you want the final fabric to be a bit chunkier and sturdier, then using a thicker yarn with the same needle/hook size will help you produce a tighter fabric. Some fibers, like cotton or linen, can also produce strong and sturdy fabric as well.
The knitting technique that the pattern uses may not be suitable for every type of yarn, even if the yarn is of the same weight as the pattern’s recommendation. The yarn’s fibers, plies, and overall texture may not be suitable for certain knitting techniques.
For example, if you are working with a fair-isle knitting technique to produce a colorwork piece, then using wool or acrylic yarn, which offers some elasticity, can help to smooth out the gaps and uneven tension often produced when you switch colors.
These issues can look very prominent when you use a yarn that doesn’t have elasticity, such as linen or cotton.
If you are using textured patterns like cables, you don’t want to use textured yarn because it would look too busy. You’ll want to avoid tweed or fuzzy yarn for these types of patterns. A nice and smooth yarn will help you show off the textured pattern much better.
A lot of clothing patterns call for the use of ribbing, where you alternate knit and purl stitches to create an elastic cuff or band for your sweater or trousers. How elastic the ribbing will be is also affected by the yarn fiber.
For example, fibers that are not very elastic, like cotton or linen, won’t produce a very elastic ribbing, whereas wool or acrylic will be extremely stretchy. If you want the final garment to have structured ribs, then you will need to use the pattern’s recommended fiber.
Some textures are created by the textures in the yarn itself, and we see this sometimes when a plain pattern is worked using stubby yarn or eyelash yarn.
These textures cannot be substituted by anything other than the texture in the yarn, so you can only substitute the fiber content or the yarn weight.
Yarn fibers can affect how the final fabric will feel against the skin – how soft, light, and breathable the final garment will be to wear.
During the summertime, you’ll want to opt for a natural fiber that feels lightweight and breathable against the skin. That’s why cotton, bamboo, linen, and hemp are popular substitutes if you are making a garment for the summer.
During the winter, a soft and thick fiber that can insulate your body, such as wool or acrylic, will be more pleasant to wear. Natural fibers like wool or alpaca tend to feel softer and more breathable, while synthetic fibers like acrylic can trap heat and moisture.
Natural fibers like wool, silk, or cotton can also feel very soft and pleasant against the skin, which is why a lot of people prefer natural fibers to synthetic substitutes. There are also yarn blends that can offer the breathability of natural fibers and the durability of synthetic fibers.
Durability doesn’t only refer to how much wear you’ll get out of a garment but also how difficult the garment is to wash and care for.
A lot of patterns recommend using wool, but wool garments often require handwashing, which can be quite time-consuming. This is especially an issue if you are making a baby garment or baby blanket since these garments need to be washed often.
This is often a big reason why people want to substitute yarn – to make the garment a bit easier to launder. In these cases, you can simply look for a more durable fiber, like cotton or acrylic, or look for a “superwash” yarn that you can machine wash.
Budget is also a big reason why people want to find a yarn substitute. Most of the time, the yarn recommended by the pattern may be too expensive and inaccessible.
Synthetic fibers are often more affordable than natural fibers like wool or silk while offering the same look and even more durability.
How To Substitute Yarn Of The Same Weight
Substituting yarn of the same weight is quite simple since using the same yarn weight and knitting needles/crochet hook size will likely give you the correct size. However, you will still need to achieve the correct gauge and how many skeins of yarn you’ll need to get.
Let’s take a look at the step-by-step.
1. Find The Yarn Requirement In The Pattern
If you are using a pattern for your garment, you may want to find the yarn requirements that are recommended by the pattern maker. Every pattern usually has a recommended yarn, how many skeins of that yarn are needed, a recommended needle or hook size, and the correct gauge.
This information is the most important information that you’ll need to substitute yarn of the same weight. The recommended yarn will belong to yarn weight, and using the same yarn weight with the recommended needle or hook size will give you the most consistent result.
2. Pick Your Substitute Yarn Based On Yarn Weight
When you have the information on what yarn weight and needle size to use, you can find a different yarn in the same yarn weight. If you don’t know what yarn weight it is, the recommended needle size is a good indication.
Refer to the chart below to match the yarn weight with the right needle size.
|Knitting Gauge (4” x 4”)
|Crochet Gauge (4” x 4”)
|1.5 – 2.25 mm
|33 – 40 stitches
|32 – 42 double crochets
|2.25 – 3.25 mm
|27 – 32 sts
|2.25 – 3.25 mm
|21 – 32 dc
|3.25 – 3.75 mm
|23 – 26 sts
|3.25 – 4.5 mm
|16 – 20 dc
|Double Knitting (DK)
|3.75 – 4.5 mm
|21 – 24 sts
|4.5 – 5.5 mm
|12 – 17 dc
|4.5 – 5.5 mm
|16 – 20 sts
|5.5 – 6.5 mm
|11 – 14 dc
|5.5 – 8 mm
|12 – 15 sts
|6.5 – 9 mm
|6 – 11 dc
|8 mm +
|6 – 11 sts
|9 mm +
|5 – 9 dc
Then, you can start to look for a good yarn substitute. Every skein of yarn comes with a sleeve that tells you the recommended needle or hook size, as well as the gauge (how many stitches and rows are needed to make a 4” x 4” square).
Using the yarn with the same yarn weight and recommended needle size as your pattern’s requirements will give you the best chance of success.
3. Gauge Swatch
Yarn weight is not the only thing that can determine the success of a knitting or crochet project. As you can see in the chart above, even in each yarn weight category, the recommended needle/hook size can vary hugely, and that can also affect how big your final garment will be.
That’s why knitting a gauge swatch with your substitute yarn is highly recommended, especially if you are making a garment that needs to fit well. A gauge swatch will tell you how many stitches and rows you will need to make a 4” x 4” square, using your yarn and the correct needle size.
Matching the gauge of your new yarn with the correct gauge in your pattern will help you make the correct size as indicated by the pattern.
But what can you do if the gauge doesn’t match? If you have to use more stitches and rows to fill up a 4” x 4” square, then your stitches are too small, and you’ll have to use bigger needles or crochet hook to make your stitches bigger to get the correct swatch.
On the other hand, if you have fewer stitches and rows in your gauge swatch than the correct swatch, then your stitches are too big. Using smaller needles or crochet hooks will help you match the gauge to achieve the right size.
A gauge swatch isn’t only useful to match gauges. It’s also quite handy if you are experimenting with colors and textures.
If you are using a textured yarn, a gauge swatch can help you see if the needle size you’re using will help you showcase the texture nicely. If you are using a colorwork pattern, then a gauge swatch that incorporates the colors can help you decide if you have the right palette.
4. Check How Many Skeins Of Yarn Is Needed
Once you have the right yarn substitute and the right swatch, then the next step to check is how many skeins of the new yarn you will need to complete your project.
Why does it matter to calculate this right away? Can’t you go back to the yarn store and get more if needed? Besides being a hassle, making multiple trips to get the same yarn can produce other issues. Your yarn may be discontinued, or the dye lot may be different.
Yarn is often dyed in big batches, and each skein of yarn has a number indicator called the “Dye Lot,” which tells you which batch of yarn your skein has been dyed in. Matching the dye lot of all your skeins of yarn is necessary to produce nice, even colors throughout your entire work.
If you use skeins from multiple dye lots in the same project, you’ll see a slight color variation between the different skeins. This may not be a big issue for colorwork patterns, but if you’re using just one color, the subtle color difference may look quite jarring.
That’s why you’ll want to calculate how much yarn you’ll need in advance so that you can get all the yarn you’ll need for your project in one go. That way, the dye lot will match, and your project will look nice and even.
In every pattern, you’ll see a sentence that tells you how much yarn is needed. Let’s use My Favourite Things’ Sweater No. 11 Pattern as an example. This pattern indicates that the total material needed is 550 (600) 700 gr. Peruvian Highland Wool, Filcolana 50 gr. / 100 m.
This means that for each of the sizes, Small, Medium, and Large, 550 grams, 600 grams, and 700 grams of the recommended yarn are needed, respectively. For this yarn, in particular, one skein is 50 grams of yarn and is about 100 meters (110 yards) in length.
You’ll want to calculate the total length that you’ll need for the entire project.
First, pick your size. For our example, we’ll use the size medium, which requires 600 grams of yarn. Divide the total weight of yarn required by the weight of each skein (100 grams); we’ll get 6 skeins.
600 grams / 100 grams = 6 skeins
For the yarn recommended by the pattern, 50 grams equals 100 meters (110 yards). Multiply the yardage by the number of skeins.
6 skeins x 110 yards = 660 yards
This means you’ll need 660 yards or 600 meters of yarn in total to complete this sweater in size M.
Now, check your yarn substitute. The sleeve of the skein will tell you the weight of the skein and how long it is.
For this example, let’s use Lion Brand Yarn Feels Like Butta Yarn. 100 grams of this yarn is 218 yards. Divide the total yardage by the yardage of each skein.
660 yards / 218 yards = ~3 skeins
That means you will need to buy 3 skeins of this yarn to complete the sweater, as indicated by the pattern.
Substituting Yarn Of A Different Weight
There are some knitters and crocheters that recommend against using yarn of different weights, but others love experimenting with producing different effects for your garment.
As a general rule:
- Using a lighter yarn and smaller knitting needles/crochet hooks will produce a smaller garment.
- Using a bulkier yarn and bigger knitting needles/crochet hooks will produce a bigger garment.
For garments that don’t need to be fitted, such as blankets, afghans, or scarves, using a different weight yarn may not matter so much. The final garment will still work and look nice if you use a different yarn weight and a different needle/hook size than the one recommended by the pattern.
However, for fitted garments, it is much tricker. Some experimentation is needed to make sure that the final garment will fit around your body nicely. Using a different yarn weight with the same needle or hook size can also produce some interesting effects:
- A lighter yarn weight with the same needles/hook size can produce light and lacy fabric.
- A thicker yarn weight with the same needles/hook size can produce bulkier and sturdier fabric.
If you want to use a different yarn weight and a different needle size, then there are some steps that you can take to figure out whether the new yarn weight and needle size will work.
Make A Gauge Swatch
A gauge swatch is always the first go-to when it comes to experimenting. It’s a short and simple way to find out the rough size of your final garment.
If you make a gauge swatch and see that the correct gauge is achieved, then congratulations, you can safely use your yarn, and your needles and the garment will turn out fine. As long as the gauge is correct, a variation in yarn weight and needle size may not matter.
However, if the gauge is different, then you will have to count the stitches and rows of your gauge swatch and do some math in the next step.
Here’s a tutorial for making your own crochet gauge swatch from Yarnspirations on YouTube.
Alter Your Pattern
Let’s use My Favourite Things’ Sweater No. 11 Pattern as an example again. The gauge required is 17 sts / 23 rows.
Let’s say you want to use a chunky yarn with a gauge of 15 stitches x 20 rows (using 6 mm needles). That means your stitches are bigger than the recommended gauge, and you’ll need fewer stitches than the pattern’s requirements to make the same size garment.
The recommended gauge is approximately 1.15 times smaller than your yarn’s gauge (17 stitches/15 stitches = 1/13).
That means if the pattern calls for casting on 30 stitches, you’ll need to cast on 30/1.15 = 26 stitches instead, using your substitute yarn and needles.
Make sure to do this for length as well as width. For example, if the pattern indicates that you’ll need 30 rows, you only need 26 rows with your substitute yarn and needles.
If you’re lucky, the math may match a smaller size’s number of stitches and rows. For example, if you want a size medium sweater, but you’re using a chunkier yarn and bigger knitting needles, then you can follow the pattern’s instructions for size Small or Extra Small instead.
Wash and Block
After finishing your garment, the last but very important step to ensure that your final garment fits nicely is to wash and block your garment.
Blocking your garment can really transform the garment and solidify its shape. If the garment doesn’t fit nicely after knitting, blocking may also help you shape the garment some more to make some last tweaks to the garment’s size.
Of course, this is not a fool-proof process. If you use a yarn weight that is significantly thinner or significantly chunkier than the pattern’s recommended yarn, then it may not work out.
However, with some experience, you can get a feel for which yarn will work and which ones won’t, and substituting yarn will be much easier the more you do it!