7 Primary Yarn Weights Categories

If you are new to knitting, you may be curious about yarn weights. Understanding yarn weight is vital because it directly impacts the outcome of your projects. Different yarn weights are used for different project types.

Additionally, the yarn weight you choose will help determine the size of the crochet hook required. Are you ready to learn everything you can about yarn weight? Then keep reading.

In this article, I will talk about the seven primary yarn weights and explain their specific applications. To make things even easier. I have included a convenient yarn weights comparison chart for quick reference.

What is Yarn Weight?

different yarn weights

When I first started crocheting, I found the term “yarn weight” confusing. Initially, I thought it referred to the actual weight of the yarn. However, this is not the case. Yarn weight actually refers to the thickness of the yarn.

If you have looked at different types of yarn, you have likely noticed a number printed on the label. This number indicates the yarn weight, which can range from 0 (lace weight) to 7 (jumbo).

Why is the Importance of Yarn Weights?

yarn weights

Understanding different yarn weights is very important for your knitting projects. Yarn weight directly relates to the thickness of the yarn. For instance, if you are working on a delicate lace project, you do not want to use super bulky yarn. Super bulky yarn would be too thick and overpower the delicate details.

On the other hand, if you are working on a cosy, thick blanket you do not want to use thin lace weight yarn. Lace weight yarn would not provide the desired warmth and coziness the blanket needs.

Selecting the appropriate yarn weight helps to ensure your projects turn out just right. The yarn weight you use will directly influence the drape, texture, and overall appearance of your knitted project. So, before you buy your yarn, take a moment to determine the correct weight for your project.

What is Yarn Ply?

The term ply refers to the number of individual strands twisted together to create a single yarn strand. Yarn can be single-ply, meaning it consists of a single strand, or it can be plied with multiple strands. Common ply numbers range from 2 ply to 14 ply.

The ply of yarn weights can affect its strength, durability, and overall appearance. It does not directly indicate its thickness or yarn weight. The thickness and weight are determined by the thickness of the individual strands used to create the yarn.

What is WPI?

WPI stands for “Wraps Per Inch.” It refers to the number of times you can wrap the yarn around an item, such as a pencil, that has a consistent circumference. By counting the wraps in an inch, you can determine the approximate yarn weight.

The technique can help knitters identify the yarn weight when the information is not specified on the yarn label, or the label is missing.

Yarn Weights by Yards/Meters

Knowing the yarn weight by yards/meters is helpful when planning your projects. It will allow you to estimate the amount of yarn needed based on the desired size of your finished project. It provides a general guideline for determining the amount of yarn required.

Standard Yarn Weight Categories

Below are the seven primary yarn weight categories. Each category is broken down to provide a clearer understanding of the characteristics and uses of each of the yarn weights. Once you familiarise yourself with the categories, you can use the yarn weight chart for a quick comparison guide.

Yarn Weight 0 / Lace Weight Yarn

Yarn Weight 0 / Lace Weight Yarn

Yarn weight 0 is also known as lace weight yarn. It is an extremely fine yarn commonly used when creating delicate and intricate knitted pieces. The yarn is often recommended for making lacework, doilies, scarves and lightweight shawls. Due to its thinness, lace weight yarn produces a delicate and airy fabric.

Yarn Weight 1 / Super Fine Yarn

Yarn Weight 1 Super Fine Yarn
Yarn Weight 1 Super Fine Yarn

Yarn weight 1 is also known as super fine yarn, sock yarn, baby yarn, or fingering weight yarn. It is similar to lace weight yarn and can be used as a substitute. However, it is important to use the appropriate knitting needles for this yarn weight.

This versatile yarn weight is commonly used for creating various items such as baby clothes, socks, lightweight shawls, scarves, and more. Its fine texture makes it a good choice for intricate and delicate projects.

Yarn Weight 2 / Sport Weight Yarn

Yarn Weight 2 / Sport Weight Yarn
Yarn Weight 2 / Sport Weight Yarn

Yarn weight 2 is also known as sport weight yarn. It is slightly thicker than lace weight yarn. It is a versatile yarn size suitable for various projects. Sport weight yarn is ideal for knitting items like lightweight socks and summer wear for babies.

It is also great for creating lap blankets, pillows, bags, and more. Yarn weight 2 provides a comfortable balance between weight and warmth.

Yarn Weight 3 / Light Worsted

Yarn Weight 3 Light Worsted
Yarn Weight 3 Light Worsted

Yarn weight 3 is also known as light worsted and DK. This yarn weight is particularly well-suited for lightweight projects. It is commonly used in knitting items such as sweaters, baby afghans, shawls, pillow covers, and more. With its midweight thickness, it creates a lightweight fabric that is warm.

Yarn Weight 4 / Worsted

Yarn weight 4 is also known as worsted, Aran, and afghan yarn. Due to its thickness, it is a popular choice for cold weather projects, such as scarves, mittens, hats, and sweaters.

It can also be used for various other projects like coasters, amigurumi, and handbags. Its versatility and ease of use make it a go-to option for a wide range of projects.

Yarn Weight 5 / Bulky Yarn

Yarn Weight 5 Bulky Yarn
Yarn Weight 5 Bulky Yarn

Yarn weight 5 is also known as chunky, bulky weight, rug, and craft yarn. It is a thick yarn that is often used to create projects quickly. It is frequently used when making chunky blankets, scarves, sweaters, hats, and more. The thickness of yarn weight 5 results in cosy and warm items that make a bold statement.

Yarn Weight 6 / Super Bulky Yarn

Yarn Weight 6 Super Bulky Yarn
Yarn Weight 6 Super Bulky Yarn

Yarn weight 6 is also known as super chunky, roving weight, and super bulky. It is an extremely thick yarn, perfect for knitting projects that require extraordinary warmth and thickness. It is commonly used to create cosy and chunky items like slippers, hats, scarves, baskets, amigurumi, blankets, and more.

With its substantial texture and thickness, yarn weight 6 produces finished projects that are both visually striking and warm.

Yarn Weight 7 / Jumbo Yarn

Yarn Weight 7 Jumbo Yarn
Yarn Weight 7 Jumbo Yarn

Yarn weight 7 is also known as jumbo and roving weight. It is a large yarn often used for creating blankets. Due to its extreme thickness, it allows you to finish projects quickly. It is perfect for making soft blankets that make a statement.

Yarn Weights Chart

To assist you in choosing the right yarn weights and knitting needles for your projects, I have prepared a convenient yarn weight chart. It includes standard US weight categories, as well as UK and Australian terms. Additionally, the chart provides information on the recommended knitting needle sizes.

Yarn Weights Comparison Chart

US WeightUKAustraliaYarn TypeWPIYards per 100 gramsMeters per 100 gramsKnitting Needle Size
#01 Ply2 PlyLace Weight30-40+500-1000600-1100US 000-1
1.5-2.25 mm
#12 Ply3 PlyBaby Yarn
Fingering Weight Sock Yarn
Super Fine
14-30380-500420-580US 1-3
2.25-3.25 mm
#23 Ply (fine/baby)
4 Ply (sport)
3 ply (fine baby)
5 ply (sport)
Sport Weight12-18300-380260-400US 3-5
3.25-3.75 mm
#3DK8 PlyDK
Light Worsted
11-15220-300210-250US 5-7
3.75-4.5 mm
#4Aran10 PlyAfghan Aran Worsted9-12190-240130-200US 7-9
4.5-5.5 mm
#5Chunky12 PlyBulky Weight Chunky Craft Yarn Rug6-9100-14090-120US 9-11
5.5-8 mm
#6Super Chunky14 PlyRoving Weight Super Bulky5-640-10040-80US 11-17
8-12.75 mm
#7N/AN/AJumbo Roving Weight1-45-4035-70US 17-50
12.75 mm +

Frequently Asked Questions about Yarn Weights

Can I substitute different yarn weights?

Yes, you can often substitute different yarn weights in a project. However, using a different yarn weight than suggested will affect the completed size and appearance of the item. If you are substituting a different yarn weight, make a swatch beforehand to ensure you get the desired outcome.

What do the numbers mean on yarn?

The numbers on yarn refer to the yarn weight. Yarn weight is categorised using a numbering system that ranges from 0 to 7. The label may also include descriptive terms such as lace, fingering, sport, worsted, bulky, and super bulky.

How do I choose the right yarn weight?

Choosing the right yarn weight depends on the specific project you are working on. Take into consideration factors such as the intended use, level of warmth, breathability, drape, texture, etc. Most patterns will recommend a yarn weight.

How is yarn weight determined?

Yarn weight is determined by the thickness of the plies and density of the yarn. Wraps per inch (WPI) is another method to measure the thickness to determine the weight.

What is yarn weight?

Yarn weight refers to the thickness of the yarn. Yarn weight categories range from fine lace weight yarn to thick jumbo weight yarn. The yarn weight affects the drape, stitch definition, and overall appearance of the finished project. 

Are you uncertain about what yarn weight you need? Consult my handy yarn weights chart for guidance.

It is important to remember that the recommended knitting needles are merely guidelines. As you work on various knitting projects, you will discover that patterns may specify different needle sizes than what the yarn weights suggest.

After reading this article, I hope you now have a better understanding of the various yarn weight categories.

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