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.

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…

… but not always.

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).

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.

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.

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.)

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…

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.

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