Yarn Weights Explained: What does it mean?

January 23, 2026

Choosing the right yarn weight can feel confusing, especially when you’re faced with terms like 4-Ply, DK, Aran and Chunky. If you’ve ever wondered which yarn weight you actually need for a project or why two yarns that look similar behave differently - this guide may help.

This yarn weight guide breaks everything down simply, so you can choose the right yarn with confidence (and avoid frogging later!)

What Does Yarn Weight Mean?

Yarn weight doesn’t refer to how heavy a ball of yarn feels in your hand. Instead, it describes the thickness of the yarn strand, which affects:

The size of your stitches
The drape of the finished fabric
Which needles or hooks you should use
How warm or lightweight the project will be

In the UK, yarn weights are usually described using names like 4-Ply, DK, Aran and Chunky, rather than the numbered system often used in the US. This can get super confusing when you're just beginning your fibre journey, but lets break this down.

Yarn Weight Chart Comparison Chart

Yarn Weight	Typical Needle/Hook Size	Common Fibres	Common Projects
Lace	1.5–2.25mm	Mohair, alpaca, silk blends	Lace shawls, delicate wraps
4ply (Fingering)	2.25–3.25mm	Wool blends, merino/nylon, cotton	Socks, shawls, lightweight garments
Sport	3–3.5mm	Wool, cotton, bamboo blends	Baby items, light garments
DK (Double Knitting)	3.5–4mm	Acrylic, wool, wool blends, cotton	Jumpers, baby knits, crochet blankets
Worsted / Aran	4.5–5.5mm	Wool, acrylic, wool blends	Sweaters, hats, scarves
Chunky	6–7mm	Wool, acrylic, wool blends	Quick knits, winter accessories
Super Chunky	8mm+	Wool, roving-style yarns	Statement knits, cosy blankets

Lace Weight Yarn: Delicate and Detailed

Lace weight yarn is the finest commonly available yarn weight. It’s lightweight, airy, and designed to create delicate fabrics with lots of drape.

Typical fibres you’ll find in lace weight yarn:

Mohair
Alpaca
Silk or silk blends
Wool blends

Lace weight is most commonly used for:

Lace shawls and wraps
Lightweight scarves
Decorative garments

Lace weight yarn is commonly held together with 4-Ply, DK or Aran weights to add texture or depth to a project.

4-Ply Yarn: (Including Sock Yarn)

4ply yarn is fine, lightweight and incredibly versatile. It is normally comprised of four separate strands are twisted together to make one cohesive strand, often creating a round, durable, and smooth yarn. But it doesn’t always mean the yarn is made from four strands. In many regions (especially the UK & Australia), 4-Ply refers to a specific, thin, lightweight category, rather than a description of its composition.

Typical fibres you’ll find in 4-Ply yarn:

Wool and wool blends
Wool blended with nylon (especially for sock yarn)
Cotton or cotton blends (often for warmer weather makes)

4-Ply is most commonly used for:

Socks (especially wool blends with nylon)
Shawls and wraps
Lightweight garments

Sock yarn is usually of 4-Ply thickness, designed to be durable and hard-wearing. Brands like Opal are particularly popular because they create socks that last while still feeling soft and comfortable. A typical sock yarn is made up of a wool and nylon blend. Depending on the brand this is normally 75% Wool/ 25% Nylon or 80/20. The Nylon adds an essential strength and resistance to heels and toes, preventing your socks from wearing our prematurely.

Sport Weight Yarn: Between 4ply and DK

Sport weight yarn sits neatly between 4ply and DK. It offers a little more structure than 4ply while still creating a lightweight fabric.

Typical fibres you’ll find in sport weight yarn:

Wool and wool blends
Cotton
Bamboo blends

Sport weight is ideal for:

Baby garments
Lightweight jumpers
Projects where you want softness without bulk

Sport weight is less common in the UK but appears more often in patterns from international designers.

DK Yarn: The All-Rounder

DK (Double Knitting) is one of the most popular yarn weights in the UK, and for good reason. It’s easy to work with, widely available, and suitable for a huge range of projects.

Typical fibres you’ll find in DK yarn:

Acrylic
Wool and wool blends
Cotton and cotton blends
Bamboo blends

DK is ideal for:

Beginner knitters and crocheters
Jumpers and cardigans
Baby items
Toys and accessories

DK yarn strikes a great balance between structure and drape, making it a go-to choice for many makers.

Aran Yarn: Thicker, Warmer, Faster

Aran yarn sits between DK and Chunky. You may also see it referred to as Worsted — particularly in patterns or yarns from outside the UK.

Typical fibres you’ll find in Aran / Worsted yarn:

Wool
Acrylic
Wool blends

Aran yarn works up more quickly than DK and creates a warmer, more substantial fabric.

Aran is perfect for:

Sweaters and cardigans
Hats and scarves
Textured stitches and cables

If you want a project to grow fast but still have good stitch definition, Aran is a great choice.

Chunky & Super Chunky Yarn: Super Cosy

Chunky and super chunky yarns are all about speed and impact. These thicker yarns are ideal when you want something warm, bold, and finished quickly.

Typical fibres you’ll find in chunky weights:

Wool
Acrylic
Wool blends
Roving-style yarns (often called single ply)

Chunky yarn works well for:

Winter accessories
Homeware
Quick gifts

Super chunky yarn is best for:

Statement knits
Oversized scarves
Cosy blankets

Hand-dyed super chunky yarns really shine here, as the thicker strand shows off colour variations beautifully.

Final Tips for Choosing the Right Yarn

Always check your pattern's recommended yarn weight
Look at metres per 100g if you’re unsure.
Always swatch, especially with garments. (I know, I don’t want to do this either!)

If you ever need to substitute one yarn for another, websites like YarnSub (not affiliated) can be incredibly helpful. YarnSub allows you to compare yarns by weight, fibre, and gauge, making it easier to find alternatives when a specific yarn isn’t available or when you want to know if yarn in your stash will work on the project you have in mind.

Choosing the right yarn weight makes a huge difference to how your project turns out. Once you understand the basics, you’ll find it much easier (and more enjoyable) to pick yarn for any project!

Looking for yarn to get started? Explore our collections of 4ply sock yarns, DK favourites, and hand-dyed super chunky yarns — all thoughtfully chosen for quality and feel ❤️

Thank you so much for reading! I hope this has been, even a tiny bit helpful for you.

Happy creating,

Emma x

Back to blog