Yarn Weights – A Heavy Subject Explained


Knitters, and weavers, and crocheters will use yarn in all different weights. Yarn weight is an indication of its thickness, not how much it weighs. The confusion doesn’t end there as I’m sure everyone who reads this blog already knows.  You can go into any yarn store, pick up three different sport weight yarns, and find three different thicknesses.

Yarn at different weights - yarn weights explained
Yarns from my stash ranging from bulky weight to lace weight

What’s going on here?

Three possible explanations:

  1. Its deliberate! That yarn manufacturing industry has evil and tricksy ways to confuse you and keep you in yarn stores for hours and hours. They know that while fretting over all the yarn choices and comparing every single available skein to every other available skein you will, sooner or later, decide to just buy them all. Or as many as your credit card limit allows.
  2. Yarn labels are not always accurate and/or honest. Sad but true. This isn’t like food or medicine and there aren’t government agencies tasked with checking the accuracy of yarn products. As far as I know, the only time falsely labeled yarn gets pulled off of shelves is when one yarn company brings a lawsuit against another.
  3. For years centuries, there just wasn’t that much commercially available yarn. Companies labeled according to their own conventions and there was no such thing as standardization. That is changing but its slow. The Craft Yarn Council has developed a Yarn Weight System that is being accepted and used. But this system does not explain why two yarns, both labeled as fingering weight, will be different thickness. 

That’s what I’m often called on to explain in my knitting and crochet classes. So I thought I’d share it here too. But first, let’s cover a few basic points.

It’s Really Not About How Much the Yarn  Weighs

Go into a yarn or craft store and pick up a ball of thick, puffy yarn. (I didn’t mean you should go right now…. come back… I have more blogging…) Look for the thickest stuff you can find and check the label. That thick, puffy yarn ball will be 100 grams. Now look around for some thin stuff. Its probably labeled as sock yarn and check the label. I bet you its 100 grams too. Most commercially available yarn is sold in 100 gram balls/skeins.

What varies is the amount of yards in those balls. That thick, puffy ball might have only 115 yards in it while the sock yarn ball will have 400 yards. Yarn weight is an old term and it meant the weight of a single yard (or meter) of that particular yarn. In our example here a single yard of that thick, puffy yarn will weigh 0.87 grams. A single yard of the sock yarn will weigh 0.25 grams. Don’t worry about figuring that out. I won’t make you do calculations! lol. Just keep in mind that the yardage in a ball of yarn is a better indication of its thickness.  

The Almost-Standard Yarn Weight System

As I mentioned earlier, this system was developed by the Craft Yarn Council and you can find their full chart at the link provided above. Here is a simple version of it:

You can find these symbols on most yarn sold in the United States today…

Label from a ball of Washable Ewe
Label from a ball of Washable Ewe

… but not always.

Label from a ball of Taiyo

The Thick and the Thin Of It – Yarns of the same weight but they look like different thicknesses

This is what’s tripping you up. This is what makes it difficult to substitute one yarn for another. This is what I’m here to help with! I can’t make yarn companies be more honest or more standardized in their labels. But I can prove to you that these two fingering weight yarns are the same (or at least very similar).

two different fingering weight yarns

These are two different hand dyed yarns from two different sources. I’ve worked with both and I can tell you they will result in the same gauge, the same number of stitches per inch, when you work with them.

fingering weight yarn under tension

In the last picture I have both yarns under tension and held them down with scotch tape. The green thins out some. The blue thins out a lot. If you made gauge swatches with these two yarns and held them at the same tension, you would get very similar (if not exactly the same) stitches to the inch.

These yarns look different in the ball because the green is three strands tightly plied while the blue is two strands loosely plied. The blue will work up softer, be puffier, and show off any pattern that relies on texture (like cables). The green with lay flatter, drape better, and show off any pattern that relies on openings (like lace). They really are the same weight… fingering weight…. just spun differently.

Here are another two examples. In this set the blue is Cascade 220 and the purple is Malabrigo Worsted. They are both worsted weight yarn.

two worsted weight yarns

Now I’ll do a test, a wraps per inch test, to show that under tension these yarns are the same thickness. (By the way, the Ravelry yarn database determines yarn weight by its wraps per inch and that is a very good thing. Kudos to raverly for making that extra effort in the name of accuracy.)

Cascade 220 is 13 wraps per inch (wpi)
Malabrigo Worsted is 13 wraps per inch( wpi)

Again the apparent differences in the yarn are from how it was spun. Cascade is 4 small strands plied together while Malabrigo is a puffy single strand.

Some help When You Buy

Yarn store owners are a tolerant breed. They will let you fondle and sniff and pet. They might draw the line at you whipping out a ruler and starting some tests though. If you buy online you can’t even touch the yarn. So how would I make a good guess to the actual working thickness of a yarn? I look at the yardage. Here is my personal method for guessing at how thick a yarn will work up. Its based on nothing more than my own experiences and while it isn’t fool proof, it will get you in the ball park of the thickness you need.

Weight yards per 100 g Examples
Bulky 110 – 130 Cascade 128
Aran 130 – 180 Manos Del Uruguay Clasica
Worsted 190 – 240 Patons Classic Wool
DK 250 – 300 Berroco Vintage DK
Sport 300 – 380 Lamb’s Pride Superwash Sport
Fingering 375 – 475 Madeline Tosh Sock
Lace 650 or more Malabrigo Lace

Some Random and Additional Thoughts

  • There is a big no-mans-land between fingering weight and lace weight. Some yarns that fall in that range are sold as light fingering or heavy lace. Maybe we need a new category?
  • Hand dyed yarns are often sold as more than 100 grams. The hand dyer started with a skein that was exactly 100 grams. Then they saturated it with dye. Afterwards it weighed more. Its weight is yarn + dye and labeled as 112 grams or something similar. But the yardage and thickness didn’t change.
  • There was no cat-fun-play-time in the making of this post. Even though the set up for these pictures looked like this…

yarn mess

I didn’t allow them to get involved at all. That meant for lots of yelling and slapping the table and spraying Febreze air freshener all over the place. But I kept them out of that mess. I’m sure I’ll pay for it later.

Print Friendly

Related Content


"There is no failure. Only feedback." - Robert Allen

12 Comments on "Yarn Weights – A Heavy Subject Explained"

Notify of
Sort by:   newest | oldest | most voted

I love your blog, always informative, interesting (and funny), I’m curious about your 2 ply 3 ply comparison though – with handspun I found the opposite – 2 ply best for lace and 3 ply for cables http://sheepyspinning.blogspot.co.uk/2015/05/plying-experiments.html

So glad you liked the little article today. Its was a bit long and the pictures were made challenging what with the Feline Overlords and all. I admit I almost gave it on this one! As for handspun versus a commercial yarn… its really just apples and oranges. i didn’t mean to imply that all two ply yarns are best for cables, just that this particular (blue) yarn was made with two low-twist singles that when plied together made for a puffy yarn. I think puffy yarns make puffy cables. I think harder, denser, higher twists yarns make for more… Read more »

it makes sense and adds another dimension – ie how much twist. Judith Mackenzie (spinning goddess) has written extensively about the number of plies and effect on lace/ cable which is why I did my little experiments. I also spun the same fibre with low twist and high twist, the difference was incredible, low twist was soft, fluffy, not such good stitch definition, high twist was like commercial sock yarn, hard wearing, good stitch definition but not as soft, they were completely different fibres.


It is amazing what you can make a single fiber source do just in how you spin it. The amount of stored energy, the twist in those fibers, will make a huge differenc ein how your sticthing looks and feels and wears.

I guess that’s why I find it all endlessly fascinating. there is always something more to try.


Thank you for the clear explanations. I’d like to hear more about how non-wool yarns fit into this system. I’ve been looking at linen and silk yarns for a project and it seems that the weight/yardage on these doesn’t fit into my usual assumptions about wool/animal fibres.

The CYC yarn weight system isn’t meant to be wool specific. It’s meant for other fibers. You can find cottons, for example labeled as sport, worsted and aran weight. Smaller cottons get numbers of course, Size 10, 30 & so on. You didn’t give me much to go on but… maybe you’re working with very fine weight yarns? If not then you might look into Classic Elite which has has several linen blended yarns and they are all DK weight (I think). Louet puts out Euroflax in lace and sport weight. But.. .and maybe here is what’s tripping you up…… Read more »
Jean Sensat

Now I understand better and am a little overwhelmed as well. But thanks for the great explanation.


You are very welcome!


This is a very interesting way and clear illustration of the problem – thanks! I’ve been looking at several British yarns online, and while I think if I could smoosh the skeins in person I could pretty quickly decide what might work for me, I’ve been trying to decode categories like Jumper Weight and Worsted vs. Woolen “Finish.” The upshot is, I’m not buying yarn, which is probably the best outcome right now anyway. But I’d like to be prepared for Yarn Buying Time. You never know when YBT will come. Could be tomorrow! 😉


YBT. Gotcha. Also known as SEX (stash enhancement experience). Also known as any day that ends in Y.

Now.. I’m off to ask google what jumper weight is. Jumpers as in sweaters? DK weight maybe? Hmm…..


It was four-ply fingering weight – which was not even among my guesses! From West Yorkshire Spinners (WYS). And yes, I really want some of it now. Quite a lot of it, actually. Oh and it was NOT what I was looking for in the first place!


That is what cruising yarn suppliers does… it leads to the buying of yarn!

So fingering weight huh? Okay.