The Most Important Things You Need to Know About Yarn Weights

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As you learn more about crochet or knitting, it becomes important to know about yarn weights. This is helpful when you follow a pattern and need to use a different yarn or when you want to make your own simple blanket. Understanding a bit about the yarn weight you’re using is crucial for success.

Yarn weight might seem confusing because of numbers and various names that all mean the same thing. This article is here to answer the most common questions about yarn weight and help you grasp the concept better.

UPDATED: DECEMBER 18, 2023 BY BRITTANY
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Picture of three medium yarn weights

In the following sections, we’ll look at the most common questions about yarn weights and what they mean for your projects.

Here’s a quick overview of the topics we will cover in this article:


What Does Yarn Weight Mean?

Yarn weight refers to the thickness or thickness range of a yarn strand. It’s like categorizing yarn based on how thick or thin it is. Knowing the yarn weight is crucial in knitting or crocheting because it affects the final look and feel of your project. Different yarn weights are suitable for various types of projects, so understanding them helps you choose the right yarn for your specific needs.

What Are Different Weights of Yarn?

You might have come across terms like bulky weight, DK weight, Aran, or worsted weight yarn. But have you ever wondered how these names came about? And why are there different names for the same yarn weight? (And no, it’s not to confuse you!)

Many of the yarns you know and like are sorted using a standard system of numbers, symbols, and names. This system, among others, was established by The Craft Yarn Council, a group that represents the major yarn companies in the industry, such as Bernat, Caron, Lily Yarns, Lion Brand, Love Crafts, Patons, and Red Heart.

This system brought consistency to the yarn industry, making it easier to create user-friendly patterns while ensuring that all yarns produced by these companies will have one of the eight recognized weights on the label.

Source: Craft Yarn Council’s www.YarnStandards.com

These symbols make up the “standard yarn weight” system for yarn products and Companies in the Craft Yarn Council. So yarns made by the companies I mentioned earlier all get a weight category, and the matching weight icon is printed on the label.

What do Yarn Weight Numbers Mean?

As you saw in the picture earlier, the Craft Yarn Council assigned numbers to yarns of different thicknesses to make it easy for both people buying yarn and those designing patterns. It’s a simple scale, starting with 0 for the thinnest yarns and going up to 7 for the thickest yarns.

Imagine each number is like a fast way to know about the yarn. If you spot the number 4 on your yarn label, that means it’s a medium-weight yarn. And even if you grab a different brand of yarn and see the number 4 again, guess what? It’s another medium-weight yarn.

How to Tell What Weight a Yarn Is

The easiest way to know a yarn’s weight is by checking the label. If it’s made by one of the Craft Yarn Council brands, you’ll see one of the symbols right there on the label. But not all yarn makers are part of the Craft Yarn Council, so in those cases, they describe it differently.

When it comes to yarn weight outside the Craft Yarn Council standards, the words used depend on where you are. It’s kind of like using a Thesaurus for words that mean the same thing—when you hear a weight term you’re not sure about, check this yarn weight chart to get a better idea.

Yarn Weights Conversion Chart

Craft Yarn CouncilUS TermUK TermAUS Term
(0) LaceLace1 ply2 ply
(1) Super FineFingering/Sock2 ply3 ply
(2) FineSport4 ply5 ply
(3) LightLightDK8 ply
(4) MediumWorstedAran10 ply
(5) BulkyBulkyChunky12 ply
(6) Super BulkySuper BulkySuper Chunky14 ply
(7) JumboJumbo

To make it clearer, the words in each row mean the same thing. You don’t have to remember them all right away, but as you keep knitting and crocheting, you’ll start remembering them.

So, which words should you use? Well, it depends on where you are in the world and where you buy your yarn. I’m located in the United States, and most of the yarn we use follows the Craft Yarn Council standards. Since that’s what I’m used to, those are the words I use when talking about yarn on this website. On the other hand, if you’re in the UK or Australia, you’re probably more familiar with the words they use.

So, it’s best to use the words from the place you’re from. Check a chart like this one if you come across a word you don’t know. At B.Hooked, we use Craft Yarn Council words in our patterns and all resources where we talk about yarn weight.

How to Tell The Yarn Weight Without a Label

If you remember the brand, try looking it up on the manufacturer’s website. They’ll always include the weight somewhere in the description.

If you have no idea what the yarn is or where it came from, compare the weight to another yarn you do have the label for. It won’t give you a definite answer, but it’s a great place to start.

Make sure you make a gauge swatch before you start the pattern so you can be certain the sizing will turn out right. If gauge is a completely new topic for you, check out my article about gauge. It’s a topic you don’t want to skip!

Yarn Weights and Hook/Needle Size

Now that you know how yarn weight is sorted in different parts of the world, you might be wondering if there’s a standard for the hook or needle size to use with it. Well, there kind of is.

On the label of yarns from Craft Yarn Council members, you’ll see a recommended hook and needle size to help you start. But what if you’re using yarn that doesn’t use Craft Yarn Council terms? No worries, just use the chart to find the equivalent.

WeightHook SizeNeedle Size
(0) Lace1.5-2.25 mmUS 1-3
(1) Super Fine2.25-3.5 mmUS 2-4
(2) Fine3.5-4.5 mmUS 2-5
(3) Lightweight4.5-5.5 mmUS 5-7
(4) Medium5.5-6.5 mmUS 7-9
(5) Bulky6.5-9 mmUS 9-11
(6) Super Bulky9+ mmUS 11-17
(7) Jumbo15+ mmUS 17+

It’s important to note that, while this is super helpful for new crocheters and knitters, it’s not the only hook or needle size that works with a certain yarn. It’s typically the hook or needle size you would need to use to obtain the gauge also listed on the yarn label.

Yarn label showing which crochet hook size will work best with the yarn.

Here’s an example of a medium-weight yarn label. Check out the middle and right blocks and notice all the info there.

The middle block is about knitting because there’s a picture of knitting needles. The right block is about crochet because there’s a picture of a crochet hook. The numbers at the bottom and right show the number of stitches, and the info at the top is a hook or needle size. Now, look at the top where it says “4 in x 4 in/ 10 cm x 10 cm.” Here’s what it means:

In a sample using a 6 mm crochet hook, you should have 11 stitches and 14 rows in a 4-inch space.

In a sample using a 5 mm knitting needle, you should have 16 stitches and 22 rows in a 4-inch space.

While this is a good place to start, think of it as more of a reference or a starting point if you’re not using a pattern. You should always use the hook size the pattern tells you.

Following this recommendation will give you an average drape and gauge. If you use a smaller hook/needle size, it’ll be stiffer, and the gauge will be tighter. On the other hand, if you use a larger hook/needle size, you’ll get a looser drape and gauge.

If the pattern tells you to use a hook or needle size different from what’s on the yarn label, it’s because that specific size gives the right drape for that project. The size mentioned on the yarn label is a starting point, but the pattern designer may have changed it to make sure the final item looks and feels just right. So, follow the pattern instructions to get the best results for your project.

Are Some Yarn Weights Better for Certain Projects?

If you’re following a pattern, you won’t have to worry much about this but if you plan to improvise a simple scarf or blanket with a stitch pattern you love or something like that, you’ll want to take note here.

While certain fiber contents work better for specific projects, figuring out the best yarn weight isn’t always as straightforward. It’s actually pretty subjective. The more you try different yarn weights and complete projects of various sizes, you’ll discover you prefer some for certain projects and not others.

For example, I tend to avoid super bulky weight yarns for projects like baby hats because they end up too bulky and awkward in such a small size.

Ask yourself these questions when deciding on the best weight for your project:

  1. How big will the project be?
  2. How much time do you have to work on it?
  3. Does it need to be durable or flexible?

It’s worth noting that projects made with thinner yarns take more time to finish, while thicker yarns take less time. So, think practically about your project and the time you have to complete it first. A lightweight yarn might not be a practical choice for a large blanket you only have a couple of weeks to finish, but it could be perfect for a hat with no deadline.

Consider drape too. “Drape” describes how the fabric flows naturally when moved or worn, and it’s influenced by yarn weight, hook/needle size, gauge, and even stitch pattern. So, when you’re looking at your yarn label and trying to decide on the hook or needle size, ask yourself this: Do you need it to be flowy and soft (like a sweater) or stiff and durable (like a basket)?

Generally, thinner yarn produces a lighter, more flexible fabric when knit or crocheted, while thicker yarn produces a more durable, rigid fabric. But, as we mentioned earlier, factors like hook/needle size and stitch pattern also play a big part in the drape of a fabric.

What projects are best with each yarn weight?

While you can use almost any yarn weight for any project, we’ve discovered that some work really well together. These suggestions come from my own experience, considering things like how the fabric hangs (“drape”) and how long it takes to complete. They’re not the only options, but it’s a handy guide if you’re not sure where to start.

(0) LaceShawls & Layering garments
(1) Super FineDoilies, Socks & Shawls
(2) FineSweaters, Light Scarves, Baby Clothing
(3) LightBaby Blankets, Sweaters & Scarves
(4) MediumHats, Scarves, Blankets & Bags
(5) BulkyBlankets, Cowls & Home Decor
(6) Super BulkyBlankets, Pillows & Rugs
(7) JumboRugs & Novelty Blankets

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