How to Make Yarn Substitutions

In my most recent survey, I asked you guys to tell me what you are interested in learning about and over and over again, you told me that you want to learn about making good yarn substitutions.
I was thrilled to hear this, as this topic has been on my to-do list for a while!

I know a thing or two about yarn substitution since I worked as a Design Consultant for Rowan for a couple of years in my late teens. Every Saturday, knitters would ask me for yarn substitutions on patterns they wanted to knit and I would point them in the right direction.

When should you make a yarn substitution?

Whilst I suggest that you use the same yarn as the designer suggests as often as you can, there are many reasons why you might want to make a yarn substitution. Perhaps the yarn is discontinued or out of your budget. Maybe you are allergic to the fibre suggested or you just don’t like the yarn.
Whatever your reason might be: if you’re going to make a yarn substitution, you have to consider several factors you should take into account in order to avoid disappointment.
Let’s be honest here: most of us have made the mistake of a bad yarn substitution. This can result in the wrong fabric handle (aka. feel). It can also result in seasonally inappropriate, ill-fitting garments and no-one wants that!
In this article, I will share the factors to consider when making a yarn substitution and a couple of fabulous resources that will help you out if you’re looking for a new yarn in a hurry!

How to Make a Good Yarn Substitution

Gauge and Weight of the Yarn

If you’re knitting something that has to fit, it is crucial that you try and match the gauge or else it will end up the wrong size. This is less of a problem with things like blankets, shawls and scarves because they can allow for a bit of size variation.
A good place to start is by checking which weight the suggested yarn is. If you’re not sure, you can look up the yarn on Ravelry and more often than not, it will be listed there. You can then use Ravelry to search for alternative yarns in that weight category.
Once you’ve got an idea of the sorts of alternatives available to you, you will want to check the yarn’s gauge. Ideally, you want it to be exactly the same as the yarn that the pattern suggested. If it’s close, but not exactly the same, you might be able to achieve the correct gauge by adjusting your needle size.
Once you’ve found “the one”, swatching is a non-negotiable (although it should be anyway!) It is crucial that you knit up a tension square to double check your gauge and make sure that you like the resulting fabric.
For those of you who are wanting to knit a pattern in a different weight of yarn, it is certainly possible, but it is way more complicated. There is a lot to say on this topic, so I shall cover it in a blog post in the near future.

Fibre Content

Not all fibres are equal. In fact, they are entirely unique in the fabrics that they create. That is why it is important that you try to match the fibre of the suggested yarn if you want to match the overall feel of the garment in the pattern.
For example, a scarf knitted in a “woolly” wool will have a lot more body and stitch definition than one knitted in a drapey silk blend. Both scarves will look wonderful, but don’t expect them to look the same.
Likewise, a Winter garment knitted in cosy pure wool will look and feel extremely different in fibres such as cotton, linen and silk.
When making yarn substitutions, it is very important to match the yarn according to the warmth, drape and texture that the pattern (and you) requires.


This might go without saying, but you can’t substitute the yarn and then expect to buy exactly the same number of skeins as the pattern suggests. It is extremely unlikely that the new yarn will have the same meterage.
To figure out how many skeins of the new yarn you need to buy, you first need to figure out how many metres/yards were used in the original garment. You then need to divide that number by the meterage/yardage in the new skeins to find out exactly how many skeins you need to buy.
For example, if you wanted to knit the medium size in my Split Stone sweater, you would need 11 skeins of Lyonesse DK at 109 metres per skein. This means that the garment needs 1199 metres in total. If I wanted to substitute this yarn with Tamar DK at 220m per hank, I should divide 1199 by 220 to give me 5.45. This means that I need 6 hanks of Tamar DK.


What kind of stitch does the pattern use? If you want to maintain the same overall look as the pattern, it’s important to take the stitch into consideration.
A knit/purl design such as my Lovelock scarf needs a yarn with great stitch definition to show off its beautiful texture. A yarn with a large halo will hide all of your work!

A lace shawl needs drape, so a stiff cotton won’t give the same effect as a wool/silk blend. Cabled fabrics require a solid colour to make the most of the texture - a highly variegated yarn will only lose the stitch. Colourwork works much better with a yarn in an elastic fibre since that’s the only way you will seamlessly close up those gaps. That’s why wool works so well in fair isle!


It is also very important to consider the context in which the yarn will be worn so that you can make the best decision on the type of yarn you use.
If you intend to wear a garment a lot, e.g. socks, you will need to look for something hard-wearing. Socks need to be made from strong fibres that can withstand the friction at the heel when wearing shoes. That’s why so many sock yarns include nylon! If you prefer to use natural fibres, Blacker Yarns have just released a new sock yarn that looks delightful. It contains mohair, which is very strong, eliminating the need for nylon.
If you’re knitting a baby gift, it’s worth considering whether the new mum will have the brain space to handwash that sweater you’re knitting! I’m not a fan of superwash yarns, however, in cases like this, it might be the better choice.
Another important thing to think about is whether you plan on wearing the knit directly upon your skin. If so, you might want to choose softer yarns for this project. Whilst some people can withstand the coarsest of wools around their neck, this isn’t the case for most.

Making Yarn Substitutions for Vintage Knitting Patterns

Vintage patterns are tricky because the yarn is no longer available. Sometimes, they don’t even include a gauge suggestion!
In cases like this, I suggest that you look on Ravelry to see if anyone has knitted this pattern before. If not, you might have to get technical. 
Look at the number of stitches suggested for your bust size and figure out how many stitches per 10cm/4" you are working with. Double check that this gauge will work with the needle suggestion they made. Then, choose your yarn based on that anticipated gauge, but check the measurements whilst you’re knitting, just in case you need to make adjustments.

Tools to Help With Yarn Substitution

Ravelry is a great resource when it comes to finding alternative yarns. Look on a pattern’s projects page to see what yarn substitutions other knitters have made. Ravelry even gives you “yarn ideas” for most patterns. You can then check on the projects using your chosen yarn to see if they’ve made any comments on the success of their yarn substitution.
I have also discovered Yarn Sub recently, which basically does all of the hard work for you! All you need to do is type in the yarn you want to substitute and it will bring up a list of potential yarn substitutions, stating their pros and cons. It is super clever!


Swatching is very important to test whether a yarn substitution is appropriate. Don’t let anyone tell you that swatching is boring - it can be really fun if you think of it as an experiment. Plus, it’s lovely to look back on all of your old projects via swatches. I keep all of my design swatches in a sketchbook with all of my design notes. My friends on Instagram love it!

How do you make yarn substitutions?

Are you a yarn substitution pro? Are there any tips that I’ve missed that you’d love to share with the Sisterhood? Please leave a comment below. Or maybe you’ve experienced a yarn disaster? I’d love to hear your substitution fails below!