Have you ever found the perfect crochet pattern, only to realize you don’t have the exact yarn it calls for and you don’t want to buy more yarn? We’ve all been there. But here’s the good news—you don’t have to run to the store or place an order just to get started. Knowing how to substitute yarn successfully with what’s already in your stash can help you save money while still getting great results.
In this yarn substitution guide, I’ll walk you through what you need to know to successfully substitute yarn, so you can confidently swap out yarns for any pattern.
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1. Understanding Yarn Weight & How It Affects Your Project
The first step in yarn substitution for crochet is matching the weight of the recommended yarn. Here’s a quick breakdown:
| Yarn Weight Category |
| Lace weight (0) |
| Fingering weight (1) |
| Sport weight (2) |
| DK weight(3) |
| Worsted / medium weight (4) |
| Bulky weight (5) |
| Super Bulky yarn weight (6) |
You can find the yarn weight for your yarn on the yarn band or yarn label. If you’re new to reading yarn labels, check out my guide to how to reach a yarn label here.
While the weight of the yarn is a great place to start, it isn’t perfect. Two yarns with the same yarn weight classification may produce very different results as one may be thinner or thicker than the other. We’ll talk more about this soon.
💡 Tip: If you want to use a slightly lighter or heavier yarn than the suggested yarn, try adjusting your hook size to achieve the correct gauge.
2. Matching Fiber Content & Other Qualities for the Best Results
Not all fibers behave the same way. Substituting an acrylic yarn in place of cotton or animal fibers can change how the project drapes, stretches, or holds shape.
Here’s a rough outline of how different fibres behave:
- Cotton – Cotton yarns hold its shape well, doesn’t stretch much (great for bags, baskets).
- Acrylic – Soft, warm, and affordable, but may be less breathable than natural fibers.
- Wool – Has great elasticity, warmth and moisture-wicking properties but may shrink or felt if not cared for properly.
- Bamboo – Super soft with beautiful drape but can be slippery to work with and lacks stitch memory (meaning that it can easily lose shape and it won’t return to its original shape).
- Alpaca – Warm, soft and luxurious but can be very drapey and lack stitch memory as well.
These are just a guideline and many yarns will have a blend of different fibers to harness the best qualities or counteract some of the negative qualities of some yarns. Even how the yarn is treated will affect how the yarn behaves. A pure wool will behave differently than a superwash wool and a mercerized cotton will behave differently than a cotton blend.
✅ Best practice: If you need to substitute a yarn, choose one with similar fiber content to keep the drape and structure close to the original pattern.
If you’re confident in your ability to judge the drape of your fabric and match it to the project’s intended drape/use, you can branch out and substitute other fibers.
Other Qualities to Keep In Mind:
Besides matching the yarn fibers, you want to consider what type of yarn construction the recommneded yarn uses. Meaning, is the yarn plied, roving, fur, chainette, eyelash yarn, etc. since differen yarn constructions affect how the yarn looks and behaves.
A roving yarn will have a very different texture and drape in your fabric than a chainette yarn will. Knowing what kind of strand the yarn is will help you get the closest match to the yarn in your pattern. If you’re not sure what type of yarn it is, look up the yarn in Ravelry’s yarn database or look at pictures of the yarn online which can help you get a good idea about what the yarn type is.
3. Understanding Yarn Yardage
Patterns often list how many skeins or balls you need, but not all skeins are the same length. When substituting yarn, always compare yardage, not just skein weight.
How to calculate yarn substitution properly:
1. Find the yardage of the original yarn (check the yarn label, pattern details or look the yarn up online in places like Ravelry or the manufacturer’s website).
2. Find the yardage of your stash yarn.
3. Divide the total yardage needed for your pattern by your stash yarn’s yardage per skein to see how many skeins you’ll need.
💡 Example 1: If a pattern calls for 600 yards of worsted weight yarn, and you have skeins of stash yarn with 150 yards each, you’ll need 4 skeins to match the yardage.
💡 Example 2: If a pattern calls for 3 – 300g balls of Bernat Blanket Yarn – look up the yarn to find the yardage per ball – 220 yds / ball. This means you’d need 660 yds for the project. If you have skeins of stash yarn with 100 yards each, you’ll need 7 skeins to match the yardage.
4. Swatching: The Key to Perfect Yarn Substitution
Once you’ve chosen your substitute yarn, it’s time to make a gauge swatch to check if it will work for your project. I know, I know – we all hate making swatches but it can make or break your project if you skip this step – especially if you’re making garments.
Why swatching matters in crochet yarn substitution:
- Ensures your stitch size matches the pattern’s gauge.
- Helps you see how the yarn drapes and behaves.
- Prevents you from making an entire project with the wrong gauge.
How to swatch correctly:
1. Use the hook size recommended in the pattern.
2. Crochet a 6×6 inch square in the stitch pattern used in the project.
3. Block the swatch the way that you will care for your piece (handwash, machine wash, steam block, etc.)
4. Compare the stitch count per inch with the pattern’s gauge.
- If your swatch is too big or you have too many stitches/rows: Try a smaller hook.
- If your swatch is too small or you don’t have enough stitches/rows: Try a larger hook.
- If your swatch can’t match the number of rows and/or stitches: You may have to try a different yarn if you’ve tried the above and you still can’t get it to match.
- If your swatch has the same number of stitches and rows as the pattern gauge: You’ve found a good match and you can use that yarn for your pattern,
5. What to Do If Your Substituted Yarn is a Different Weight
Sometimes, you find a yarn you really want to use, but it’s a different weight than what the pattern calls for. Here’s how to adjust:
Using a thicker yarn than the pattern suggests:
- Use a larger hook to maintain drape. For amigurumi, use a larger hook size than recommended but ensure you can create a tight fabric with it (I typically start with a hook size 2 sizes smaller than the yarn label and go from there).
- Adjust stitch counts and work with the measurements given in the pattern. This does not really work with garments or fitted items like hats but is great for blankets, scarves and non-fitted accessories.
Using a thinner yarn than the pattern suggests:
- Double or triple up your yarn to match thickness. Check out my tutorial for how to crochet with the yarn held double here.
- Increase the stitch count to maintain size (again, doesn’t work for most garments).
6. Using Multiple Yarns from Your Stash in One Project
If you don’t have enough of one yarn, you can blend multiple stash yarns in creative ways:
- Hold two strands together to create a thicker yarn (e.g., two strands of sport weight can substitute for worsted weight).
- Use different colors in a striped pattern to use up partial skeins.
When mixing yarns, I personally prefer to use the same yarn fiber throughout however, if you don’t mind mixing wool and acrylic, for example, because you just want to use up the yarn, go for it. However, this works best for non-fitted items like blankets and scarves.
6. Use Online Tools To Help Find The Best Substitutes
If you’re not sure where to start with yarn substitution—or if you just want to double-check your choice—there are some fantastic online tools that make the process a whole lot easier.
- Yarnsub.com is one of my go-to resources for finding yarn alternatives. It’s a free site that lets you search for a specific yarn and instantly shows you a list of similar yarn ideas, complete with information on yarn weight, fiber content, and even how good of a match it is. It also lets you know if the substitute is still available and includes user feedback when possible. I especially love that it gives you multiple substittue yarn choices that can be filtered by price range and it gives you information on whether the fabric may be denser or thinner than the yarn you searched. It’s a great shortcut to help find the right substitute faster.
- Ravelry’s yarn database is another incredible tool. If you know the yarn your pattern calls for, you can look it up on Ravelry to get detailed information on yardage, weight, fiber blend, and user reviews. You can even browse through projects made with that yarn to get a feel for how it looks and performs. If you already have a yarn in mind for substitution, Ravelry can help you compare it to the original by pulling up details like gauge, hook size recommendations, and more.
These tools take a lot of the guesswork out of yarn substitution—and when paired with swatching (yes, I’m still going to nudge you to make a swatch!), they can help you feel confident that you’ve made the right call.
Final Thoughts:
Learning how to substitute yarn empowers you to crochet with what you already have— no more stalled projects or unnecessary spending. By following this yarn substitution guide, you’ll be able to confidently swap out yarns while keeping the look, feel, and fit of your projects just right.
Now it’s your turn! Have you ever substituted yarn in a crochet project? What’s your go-to stash yarn? Let me know in the comments! 👇
Check out some of my other recent tutorials!
- Ultimate Guide to Crochet Hook Sizes for Beginners
- How to Read Crochet Patterns for Beginners
- Granny Stripe Stitch
- Crochet Shell Stitch
- Royal Ridge Stitch
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