Can I Use a Different Weight Yarn for My Project?

Have you ever found a project you love, but you don’t love the yarn they use and you wonder, “Can I substitute that for a different weight yarn?” The quick, one word answer is no. BUT, there are a few small instances where you can use a different weight yarn and your project might be ok.

Can I substitute a different weight yarn for my crochet project?

So, when can I actually substitute yarn for a different weight? 

The more elaborate answer to the “no” above is, it will usually work on projects where gauge doesn’t matter. Do not try to substitute on garments or anything with shaping. Most scarves, dishcloths/washcloths, and even some blankets will be ok, but you will need to test it first. Here’s why:

If you use a smaller weight yarn than what is called for, your project will come out smaller.

If you use a bulkier weight yarn, your project will come out bigger.

How much bigger or smaller is what you need to determine.

Make Sure the Different Weight Yarn Will Work

Checking to make sure this will work is going to save you from possible disappointment in your end results.

Choose Your Yarn & Hook – Pick the yarn you would like to substitute with, and then look at the pattern. If the original project uses a hook that is 2 sizes larger than what is called for on the label, then use a hook 2 sizes larger than what is called for on your replacement yarn also. This will give you a good starting point.

Make Two Swatches – Most patterns come with a gauge swatch. Work up two gauge swatches – one with the yarn & hook the pattern calls for, and one with the replacement yarn and hook of your choice . (You can also use the first few rows of the pattern if no gauge swatch is provided). Use that gauge swatch and compare sizes.

Measure the Difference – There will probably be a noticeable difference in the two swatches, but it may not matter to you. For example, a smaller more lightweight scarf would just be more appropriate for warmer days and a bulky thicker & wider scarf would be for cold winter days. Trying this to make sure you will be happy with your results is key.

How #4 yarn compares to #5 yarn on the same project.

My Results…. 

For the original Valentina’s Love Infinity (left photo above), I used  Lion Brand Wool-Ease Thick & Quick (#6 Super Bulky) &  Size – Q (15.75 mm) hook.

For the blush colored remake (right photo above), I used I Love This Yarn! in Rosy Cheeks (#4 worsted weight yarn) & an L/11 (8 mm) hook.

The finished dimensions were as follows:

#6 yarn – approx. 11″ wide x 57 ” long.

# 4 yarn – approx. 5″ wide x 28″ long.

While there is a big difference in size, the remake is a good size for a lighter weight cowl.

To get the free Valentina’s Love Cowl pattern CLICK HERE.

Most of the time you may decide you don’t like it, or it won’t work. But there may be occassions where the results will surprise you. Try it and see if you like the way it looks. I’d love to see!

32 thoughts on “Can I Use a Different Weight Yarn for My Project?”

  • Am trying to make an amigurumi “roast turkey”. It’s a tiny pattern and I need it to be bigger. Tried changing the pattern but that didn’t work. Calls for a #4 yarn and I am thinking of using a bigger bulkier yarn and keeping her pattern the same. Do you think it will come out bigger like I want??

  • Do you think that for amigurumis its ok to use slightly different yarn? The two yarn im thinking of are both categorized as Worsted, but one suggests a 4.5mm hook while the other suggests a 5mm hook.

    • Hi Anna,
      That sounds about right. The reason you use a worsted weight yarn with the smaller hook(s) is because you want the stitches tighter so that the stuffing won’t come out.

  • I’m making a whale for my mother in law. The pattern calls for #4 medium yarn and I want to use #6 super bulky. The pattern says it will be 17inches tail to tip using suggested yarn. Do you think it’ll come a huge monster whale if I change yarn and still follow pattern normally? Or is there an easy way to deduct a few stitches on the initial row and continue that way?
    Thank you????

    • Hey Chelsey, is there a gauge swatch size included with the pattern? If it gives a gauge X sts and X rows = 4 inches you could take the #6 and work up the same number of stitches and see how much bigger it would be. My guess is it would add quite a bit to it, but without doing math, etc I’m not exactly sure how much bigger.

  • I would love to make the American Flag throw — but would like it a little smaller — can I use DK rather than worsted yarn and if so, based on yarn gauge is correct, what size would you project the final throw to be??

    • You’d have to give it a try. If it’s between 4″ and 4.5″ on the last round of the increases it should end up the same size, but let me know if you have more questions so I can try to help you adjust it.


  • Thanks for and easy to understand blog. I am looking for yarn for a self stripping blanket and I am having trouble finding the right weight in a color I like. Your post makes me feel like I can work with what I did find.

  • I need to make a baby blanket for a gift, but I have resolved not to buy yarn until I have greatly reduced my stash. I have a lot of worsted weight yarn but the patterns I really love call for either baby or sport weight yarn. I have some #2 and #3 but only a skein or two of each color (I want pink or white). Do you have any suggestions (besides biting the bullet and buying the lighter weight yarn?

    • If you were to use a baby blanket pattern that called for #2 or #3 and substituted #4 yarn in it’s place you would just end up with a larger blanket. The other option is if the pattern has the multiple in it (Ex: it will say something like “mult of 4 + 1”) you can adjust the number of chains by taking them out 4 at a time (4 for this example) and that would reduce the size. It may take some playing with to get a size you want but it would be doable.

  • I want to use a #5 yarn for an Afghan pattern (“Fast and Easy Light and Lacy Afghan”) that calls for #4. The pattern calls for a J hook, and the #5 yarn I like also suggests a J hook on the wrapper. How much bigger do you think it will come out? Should I reduce the number of stitches, and if so, by what proportion? Of course, it doesn’t have to be exactly the size the pattern states.
    Here is what the pattern says:
    Measurements: Approx. 49.5in. x 66in./126cm. x 168cm.

    Hook Size J-10 (6mm.) or size needed to obtain the gauge.

    Gauge: In pat: One rep of 10 sts = 3in.; 6 rows = 3in.

    Thanks in advance for your guidance!

    • Hi Susan! I have no idea why this comment/question is just showing up on my blog now. I’m so sorry! I may be too late but I would suggest trying a gauge swatch to see if it matches what the designers gauge is. It would be really hard to figure out how much yarn without having any idea what that is.

  • Hiya, thank you for the informative post! I was hoping to make a hooded blanket for my nephew but wanted to use a #5 velvet type yarn rather than the #4 the pattern calls for. I am okay if the blanket comes out larger but was wondering if there was a way to figure out how much I should buy in the new yarn? Would you just buy the same amount of yds the original pattern calls for even though it is a bulkier weight? I hope that makes sense!

    Thanks in advance!

    • Hi Caisha,
      You will need more yarn but I don’t know how much more. It would depend on whether you’re making the same size (same number of beg chs) or are you making it the same size and reducing the number of chains so the finished size will be the same?

  • This probably seems like a dumb question but I’d like to make this crochet whale ( and it uses weight 4 yarn but I’m thinking of a weight 6 yarn. The problem is I don’t know how much yarn I should purchase for this project. Do I buy the same amount (in terms of length of yarn) written in the pattern which was based on using weight 4 yarn?

  • My daughter collects elephants. I am currently making a baby blanket that uses chain one and skip stitch to create the outline of an elephant. My daughter is a grown woman so naturally I don’t want to give her a baby blanket. If I change to a worsted weight yarn and larger hook but follow the same pattern, do you think it will work or will the pattern not come out looking as it should?

    • I think the pattern should change proportionately but I don’t know how much bigger it would be. Maybe throw size? You can always do a small swatch with the yarn and hook you want to use and compare the swatch size of the baby blanket. Then you can try to get an estimate of how much larger it will be.

  • Hi! So I bought a pattern a while back for an amigurumi alien and made it with the yarn and hook that were suggested but I’d love to be able to do it with a thicker yarn. The original was with a hook of 2mm (could be done with 1.5 or 2.5). Now I’d love to make this one with way bulkier/thicker yarn and obviously a bigger hook as well and I was wondering whether there was a way of doing it without having it come out as a HUGE alien hahaha. Like is there a way for me to change up the amount of stitches and it still working out? If so, how hahaha?

    • I wouldn’t suggest changing stitch counts because, unless it’s an easy pattern, the finished product may not look the same. I would suggest going up slightly on yarn and hook size instead and keeping the instructions the same.

  • This is a question, not a reply. I have a beautiful sweater pattern that calls for 2 ply yarn and I would like to use 3 ply yarn to make it heavier. I know it will come out bigger; but if I use a smaller hook (and make the gauge swatch first), will it come out nicely? Thank you for your help. (:

  • I need help or advice, I have a pattern for a poncho that says to use #4 yarn and a 6mm hook, I have got #3 yarn and not sure what hook to use, I know that by going up hook sizes it going to look holey. The gauge swatch is 13hhdc and 11.5 rows = 4 inches, can I make my #3 yarn work with the pattern or am I better off to look for yarn in the size #4

    • Yes, if you go down a yarn size you will also want to go down a hook size (or 2) to prevent it from getting holey. Just remember it will make the whole project smaller.

  • I am making a crochet animal. I’ve used this pattern before from a kit with light weight #4 yarn and 10mm craft eyes. I’ve found similar yarn in a medium yarn and I think I can pull it off I’ve taken all hook and stitch factors into account, but should I purchase 10mm eyes or size up to 12mm eyes if I want to keep the same aesthetic?

    • Do you already have 12mm? I would say, if you have both sizes, when you get to that point try them both and see which ones look better. I’m thinking you might like the 12mm better.

  • I have a question (and thank you for the post!). I would like to make this for my first crochet project:

    I originally looked at a different version of the same garment and bought sport weight yarn and a size F hook based on those instructions. But the above link calls for a D hook. I want my finished product to look identical, or very close to, what is pictured in this link. Will sport weight yarn and a size F hook replicate this look if I pull the stitches tight? Should I buy a D hook, and would a D hook work with sport weight yarn which recommends a minimum 3.75mm hook?

    Thank you!

    • You can try to just crochet tightly, but with 2 sizes larger of a hook I don’t know if it will look/be exactly like the one in the photo. If there is a gauge you can try to see if you can get it to match.

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