The Essential Guide to Yarn Weight 
Yarn weight can be a little confusing at times. Here’s what you need to know so you can fully understand yarn weight and how it’s categorized.
This guide was designed to answer all your questions about yarn weights like what does yarn weight mean? What is “standard” yarn weight? And what do yarn weight numbers mean? We’ll show you how to tell what your yarn’s weight is and give some recommendations for what hook/needle size to use with it. And finally, we’ll show you a yarn weight chart and some basic project recommendations by yarn weight. Basically, we want this to be your go-to guide for all things yarn weight.
- What Does Yarn Weight Mean?
- What Are Different Weights of Yarn?
- What Do Yarn Weight Numbers Mean?
- How to Tell What Weight a Yarn Is
- Yarn Weight and Hook/Needle Size
- Are Some Yarn Weights Better for Certain Projects?
- What Projects Are Best With Each Yarn Weight?
What Does Yarn Weight Mean?
Although the term “yarn weight” seems like it should be an actual measure of weight (like the weight of a skein of yarn), it’s really refering to the thickness of the yarn. So the next time someone asks you “what yarn weight is that?”, they’re really asking “how thick is that yarn?”
So this leads us to our next question…
What Are Different Weights of Yarn?
You’ve probably heard of bulky weight, DK weight, aran or even worsted weight yarn but how did they get their names? And better yet, why are different names given to the same weight of yarn? (and the answer isn’t to confuse you!)
Many of the yarns you know and love are categorized using a standard system of numbers, symbols and names. These standards (among others) were put in place by The Craft Yarn Council, an organization that represents the leading yarn companies in the yarn industry including Bernat, Caron, Lily Yarns, Lion Brand, Love Crafts, Patons and Red Heart. This system brought uniformity to the yarn industry making it easier to prepare consumer-friendly patterns while ensuring all yarns produced by these companies will include one of the eight recognized weights on the label.
Source: Craft Yarn Council’s www.YarnStandards.com
So if you ever find yourself wondering “what is standard yarn weight?” Collectively, these recognized symbols are what we refer to as the “standard yarn weight” system for the products of yarn companies which are a part of the Craft Yarn Council.
All yarns manufactured from Bernat, Caron, Lily Yarns, Lion Brand, Love Crafts, Patons and Red Heart are assigned a weight category and have the coordinating weight icon printed on the label.
These brands are yarn members of the Craft Yarn Council and have therefore adopted these guidelines. However, that isn’t the case for every yarn you come across. Many yarns available in parts of Europe use different terminology altogether. If you come across any of these yarns you probably found yourself googling, what yarn weight is aran? Or, what yarn weight is DK? Or, what yarn weight is 4 ply? We’ll get to that in just a bit, but first…
What Do Yarn Weight Numbers Mean?
As you saw in the image above, Craft Yarn Council yarns of all thickness were assigned a number to make it easily identifiable by consumers and designers alike. It’s a simple scale, 0 being the thinnest of the yarns and increasing in thickness up to 7 which is the thickest recognized yarn weight.
Think of each number as a quick identifier. See the number 4 on your yarn label? That’s a medium weight. And if you pick up another skein of yarn, a different brand altogether, and see the number 4 again, you’re looking at another medium weight yarn.
How to Tell What Weight a Yarn Is
The best way to identify a yarn’s weight is to look at the label. If the yarn was manufactured by one of the Craft Yarn Council brands, you’ll find one of the symbols printed directly on the label. But not every manufacturer of yarn is a Craft Yarn Council member, and in those instances it will be described in a different way.
Outside of Craft Yarn Council yarn weight standards, the terms used are based on region. Just as you would refer to a Thesaurus for a list of words that mean the same thing, refer to this yarn weight chart when you hear a weight term you’re less familiar with.
|Craft Yarn Council||US Term||UK Term||AUS Term|
|(0) Lace||Lace||1 ply||2 ply|
|(1) Super Fine||Fingering||2 ply||3 ply|
|(2) Fine||Sport||4 ply||5 ply|
|(3) Light||DK||DK||8 ply|
|(4) Medium||Worsted||Aran||10 ply|
|(5) Bulky||Bulky||Chunky||12 ply|
|(6) Super Bulky||Super Bulky||Super Chunky||14 ply|
To clarify, the terms in each row are synonymous and although you don’t need to remember them all right away, as you keep knitting and crocheting, you’ll eventually start memorizing them. So which terms should you use? Well that will depend on where you are in the world and where you buy your yarn. We’re located in the United States and much of the yarn we use for projects and tutorials follow the Craft Yarn Council standards. Since that’s what we’re used to, those are the terms we use to share projects and chat with our friends about yarn. Conversely, if you’re in the UK or Australia, you’re likely more familiar with the terms they use in these areas.
Hence, it’s best to adopt the terminology of the region you’re from and refer to a chart like this one when you encounter a term you’re unfamiliar with. Here at B.Hooked you’ll find Craft Yarn Council standard terms used in our patterns and all resources where yarn weight is mentioned.
But what if you don’t have the label?
If you still remember what brand the yarn is, trying looking it up on the manufacturer’s website. They’ll always include the weight somewhere in the description. If you have no clue what the yarn is or where it came from, it’s best to compare the weight to another yarn you do have the label for. This won’t give you a definitive answer but it’ll be a good start.
Yarn Weight and Hook/Needle Size
Now that you understand how yarn weight is categorized and referred to in different parts of the world, you might find yourself wondering if there is also a standard for the hook or needle size to use with it. You’re in luck…sort of.
Printed on the label of all Craft Yarn Council member’s yarn, you’ll find a recommended hook and needle size to get you started. But what if you’re using a yarn that doesn’t use Craft Yarn Council terminology? Don’t worry, just use the chart to figure out the Craft Yarn Council equivalent.
|Weight||Hook Size||Needle Size|
|(0) Lace||1.5-2.25 mm||US 1-3|
|(1) Super Fine||2.25-3.5 mm||US 2-4|
|(2) Fine||3.5-4.5 mm||US 2-5|
|(3) Lightweight||4.5-5.5 mm||US 5-7|
|(4) Medium||5.5-6.5 mm||US 7-9|
|(5) Bulky||6.5-9 mm||US 9-11|
|(6) Super Bulky||9+ mm||US 11-17|
|(7) Jumbo||15+ mm||US 17+|
It’s important to mention that although this is incredibly helpful for new crocheters and knitters, it’s not the only hook or needle size that can be paired with a particular yarn. Think of it as more of a reference or a starting point if you’re not sure. Following this recommendation will get you a very average drape and gauge. Then as you decrease the hook/needle size, you’ll create a stiffer drape and tighter gauge. Alternatively, if you increase hook/needle size you’ll create a drape and gauge that’s more loose.
Are some yarn weights better for certain projects?
While some fiber contents prove better for certain projects, the answer isn’t as straight forward when talking about weight. The answer as it turns out is pretty subjective. The more you experiment with different yarn weights and finish projects of all shapes and sizes, you’ll find yourself more fond of some for certain projects and not of others.
Consider these questions when deciding what weight is best for your project:
- How big is the project going to be?
- How much time do you have to work on it?
- Does it need to be durable or flexible?
It goes without saying, projects worked with thinner yarns will take more time to complete and thicker yarn will take less time to complete. Therefore, think practically about your project and the time you have to complete it first. A lightweight yarn wouldn’t be a practical choice for a large blanket you only have a couple weeks to finish but it might be a great choice for a hat you want to make without a deadline.
Something else to consider is drape. “Drape” is a term used to describe how the fabric flows naturally when moved or worn and it’s heavily influenced by yarn weight, hook/needle size, gauge and even stitch pattern. So when you’re sitting there looking at your yarn label and trying to figure out what hook or needle size to use, ask yourself this…do you need it to be flowy and soft (like a sweater) or stiff and durable (like a basket)?
Generally speaking, thinner yarn when knit or crocheted will produce a lighter, more flexible fabric while thicker yarn will produce a more durable, rigid fabric. But, like we mentioned earlier, additional factors like hook/needle size and stitch pattern play a big part in the drape of a fabric. So it’s best to make a little test swatch with your chosen yarn, hook/needle and stitch pattern to make sure it’ll turn out as you want.
What projects are best with each yarn weight?
Although you can use just about any weight for any project, there are some we found to work really well with one another. We based these recommendations on our own experience taking drape, and work time into consideration. They’re definitely not the end all be all, but it’s a good reference if you’re feeling a little stuck.
Shawls & layering garments
Doilies, socks and shawls
Sweaters, light scarves, baby clothing
Baby blankets, sweaters and scarves
Hats, scarves, blankets and bags
Blankets, cowls and home decor items
Blankets, pillows and rugs
Rugs and blankets
Furthermore, when trying to decide which yarn weight to use for your project ask yourself these two questions
- How much time do I have to finish this?
- How does the fabric need to feel?
Since thinner yarns on the weight scale will generally have a nice drape and thicker yarns will be a little more stiff, you can use this knowledge when deciding which yarn thickness is best for your project. Thinner yarns will take longer to work up while thicker yarns will work up in a fraction of the time. And if this all sounds a bit confusing, just start with a swatch so you can see what we’re saying in action.