How To Substitute Yarns When Using Vintage Knitting Patterns

Yarn subbing is a pretty advanced topic apparently, that’s what i found out when I was in depth researching it anyway. My knitting skills at the time of writing are limited to cast on, knit, purl, knit 2 together and bind off at the moment so it feels kind of odd writing this post, I feel very underqualified.

I’m writing this post because I recently started selling some of  my granny’s knitting patterns on Etsy. I’m keeping loads of them, and I am trying to learn how to knit. But as you know sewing is more of a priority to me and sewing stuff costs money so selling some of the patterns I didn’t want, seemed like a no-brainer. (shameless plug: GO CHECK OUT MY SHOP:D)  ANYWAY when you use a vintage knitting pattern you can’t use the recommended yarn because it doesn’t exist anymore. At first I was quite deflated because I had all these patterns I thought I couldn’t use but it actually isn’t that hard to substitute the yarn. Here is basically all you have to do.


Consider all of these things:

  1. The weight of the recommended yarn. Yarn weights haven’t changed much since the 60’s so if the recommended yarn is a DK that’s where you start your search. If the pattern is older than that you may have to look at a slightly thinner yarn, but it’s still best to start with the stated yarn weight category and look at a thinner yarn if you can’t find what you’re looking for.
  2. Needle size. This will give you another clue about the size of the yarn, you will have good results if you buy a yarn with the same recommended needle size.
  3. The pattern tension. Most online yarn retailers & Ravelry have information about the tension of different yarns. If you find a yarn with a matching or similar tension to the patterns recommended tension, it should work.
  4. The yarn fibre. Sometimes the pattern will say what fibre the recommended yarn is, sometimes it won’t. Strictly speaking, you’ll have better results if you substitute with the same fibre. Again, I hold my hands up, I’m not a knitter but here’s my 2 cents on yarn fibres. I don’t think it matters a lot. As long as you take the characteristics of the fibre into account you could pretty much sub with whatever you want. Just know what you’re doing with it. If you sub with cotton, it will be cooler and stretch a decent bit. If you sub with acrylic, you can’t iron it. I’m like 30% vegan so I don’t want to use wool anyway because I think it’s mean, any pattern that calls for wool, I’ll be knitting up in acrylic. EXCEPTION. Any pattern that calls for steeking (basically cutting the yarn and picking up stitches) is best done in a sticky, fluffy wool yarn. If you don’t use that kind of yarn it won’t be stable when you cut it and will probably unravel. I’m just putting this in as a side note, if you are ready to do a pattern with steeking, you know 100x more than me about knitting and you don’t need this blog post.

Found a yarn?… Here’s how much to buy. 

If you’ve found a good match then they should be similar weights (different fibres weigh differently though so keep that in mind) Some basic maths will help you figure out how much to buy. Don’t buy the bare minimum though, buy one or two extras depending on the size of the project.

Here’s some examples

If the pattern calls for 5 40g balls of the recommended yarn, and the yarn you have chosen to substitute with comes in 50g balls.

Multiply the Original yarns ball weight by the number of balls needed to find the total weight needed. eg. 5 x 40g = 200g

Then divide this total weight by the ball weight of your NEW yarn. eg. 200g divided by 50= 4. That means you need 4 balls.

If your pattern is relatively small, get an extra skein just in case, if it’s a big pattern get 2 or 3 extra.

The video “math for knitters” that I linked below is helpful with deciding how much to buy.

UPDATE: One of my lovely customers, Michelle from Gifted Goodies, sent me this advice about yarn substitution:

“What I normally do is research the yardage on the internet. You can usually find it somewhere. I normally check Ravelry first. If the yarn needs 5 balls and each ball is 100yards and the yarn I want to use is 150yards, I multiply the yards by balls -(100×5=500yards) then divide it by the yardage of the other yarn (500/150=3.33). So I’d buy 4 balls to be on the safe side. Although sometimes I will get 5 just to be doubly sure.”

This would be a lot more accurate than the method I shared above, so if you can find the original yardage, that is the method you’ll want to go with.


I highly recommend you watch & read all these thingys. These people know more than me and will provide you with all the knowledge you need.

Here are some better blog posts/ articles than mine. Working With Vintage Knitting Patterns – an in-depth article covering yarn substitution, needle size & sizing. The sizing section is scary but I don’t typically sell reaaally old patterns without size information so don’t be put off by that.

How to adapt a vintage pattern for modern yarn – another blog post about yarn substitution.

Here are some books that will be of use to you when using vintage knitting patterns (These are amazon associate links, please read disclosure)

Knit Back In Time: Techniques for Updating Vintage Patterns – Shows you how to alter vintage knitting patterns for use today and shows how to alter modern patterns for a vintage look.

Knitting Pattern Essentials: Adapting and Drafting Knitting Patterns For Great Knitwear – A slightly more advanced text to help you adapt the pattern if you need to.

I hope this blog post was helpful, I’ll try to keep it updated as I learn new things. Again, if you haven’t already I’d really appreciate it if you could check out my vintage knitting pattern store. All the money I make will go towards any supplies/ online classes I need to study sewing &pattern cutting intensively.