A Guide to the Standard Yarn Weight System

Do you need help with selecting a suitable yarn for a project? How do you know if the yarn you have is the right thickness for your knitting, weaving, or crochet? The answer is simple: with the help of the standard yarn weight system!

The thickness of yarn can have a significant effect on how your project will turn out. If you have gone shopping for yarn before, you most likely have observed that there are many types of yarn out there. With so many different colours, textures, and fibre options, knowing what to look for can be pretty challenging and overwhelming. It is essential, especially for beginners, that you understand the yarn weight system, even when following a pattern.

Read on for more detailed explanations of these yarn weights. 

Whether you are a weaver, knitter, crocheter, or embroiderer, knowing the yarn weight standards is important in creating successful craft projects. By determining the appropriate yarn to use, you will also be able to find what size needle you should use or how many stitches per inch you want.

For example, if you are making a blanket that requires a lot of stitch density, such as a throw or shawl, you may want to start out with a heavier yarn. On the other hand, if you are making something that needs less stitch density, such as baby booties, you might choose a lighter weight yarn.

Our yarn weight conversion chart, based on the Craft Yarn Council standard yarn weight system, will help make it easier for you to know your yarn’s weight, as well as what knitting needle size and crochet hook size to use. This chart will also help with yarn substitution.

The chart above is a guide only and reflects the most commonly used gauges for specific yarn categories. Determining a gauge range can be challenging, especially for lace weight yarns, so it’s always best to adhere to the gauge specified in your pattern.

Please note that steel hooks measure differently from regular hooks. The bigger the number is for steel hooks, the smaller the hook will be. Regular hook sizing is the opposite.

Also referred to as thread, cobweb, 10-count, and fingering yarn, lace weight yarn is mainly used for knitting lace, shawls, thin cloths, dollies, and other airy, light, and delicate pieces.

In the UK, this yarn weight is also known as 1ply but is considered 2ply in Australia. It measures 600 to 1100 meters per 100 grams and measures between 30 to 40 wraps per inch. This very thin yarn is compatible with 1.5mm to 2.25mm (000-1) knitting needles and 2.25mm (B-1) regular crochet hooks or 1.6mm to 1.4mm (6, 7, 8) steel crochet hooks.

Superfine yarn is also commonly known as sock, fingering, or baby weight yarn. It is used to produce a variety of knits, including shawls, socks, light baby clothes and accessories, and more.

In the UK, this yarn weight is also known as 2ply but is considered 3ply in Australia. It measures 420 to 580 meters per 100 grams and makes about 14 to 30 wraps per inch. This yarn is compatible with 2.25mm to 3.25mm (1-3) knitting needles and 2.25 to 3.5mm (B-1 to E-4) crochet hooks.

Commonly referred to as sport weight or baby weight, fine weight yarns are used to create light sweaters, baby garments and accessories, socks, wraps, and more.

In the UK, this yarn weight is also known as 4ply but is considered 5ply in Australia. It measures 260 to 400 meters per 100 grams and makes about 12 to 18 wraps per inch. This yarn is compatible with 3.25mm to 3.75mm (3-5) knitting needles and 3.5 to 4.5mm (E-4 to 7) crochet hooks.

Lightweight yarn is also called light worsted or jumper yarn. It is used for lightweight sweaters and scarves for adults and heavier baby items.

In the UK, this yarn weight is called DK (double knit), while it is known as 8ply in Australia. It measures 210 to 250 meters per 100 grams and makes about 11 to 15 wraps per inch. This yarn is compatible with 3.75mm to 4.5mm (5-7) knitting needles and 4.5 to 5.5mm (7 to I-9) crochet hooks.

Commonly known as worsted and Afghan weight, or Aran weight in the UK, medium weight yarn is used for making blankets and outdoor wear, such as sweaters, scarves, hats, and mittens.

In Australia, this yarn weight is equivalent to 10ply. It measures 130 to 200 meters per 100 grams and makes about 9 to 12 wraps per inch. This yarn is compatible with 4.5mm to 5.5mm (7-9) knitting needles and 5.5mm to 6.5mm (I-9 to K-10 1/2) crochet hooks.

Bulky yarn is called craft, rug, and heavy worsted yarn, or chunky in the UK. It is used to make sweaters, jackets, blankets, chunky hats, and many more.

In Australia, this yarn weight is equivalent to 12-14ply. It measures 90 to 120 meters per 100 grams and makes about 6 to 9 wraps per inch. This yarn is compatible with 5.5mm to 8mm (9-11) knitting needles and 6.5mm to 9mm (K-10 1/2 to M-13) crochet hooks.

Super bulky or roving yarn is called super chunky in the UK and 16ply in Australia. It is used to make heavy blankets and rugs and cold-weather garments, like jackets and sweaters.

It measures 40 to 80 meters per 100 grams and makes about 5 to 6 wraps per inch. This yarn is compatible with 8mm to 12.75mm (11-17) knitting needles and 9mm to 15mm (M-13 to Q) crochet hooks.

Jumbo weight is referred to as super chunky and roving in some countries, which tends to create confusion between jumbo and super bulky. In Australia, this yarn weight is equivalent to 20ply.

Great for making heavy blankets and rugs, as well as arm knitting projects, this yarn measures 40 to 80 meters per 100 grams and makes about 1 to 4 wraps per inch. It is compatible with 12.75mm and larger (17 and larger) knitting needles and 15mm and larger (Q and larger) crochet hooks.

What is a ply? Individual strands of yarn are plied or twisted together to increase their strength and uniformity. A single strand of spun yarn is called a single, not 1-ply. Yarn only has a ply after singles are plied or twisted together. A 2-ply yarn is created from twisting together two singles, a 3-ply yarn is made from three singles, and so on.

The reason Thread Collective has adopted the US standards is that in Australia, the yarn guidelines refer to 2-ply, 4-ply, 10-ply, etc. The use of different rules creates confusion, especially when it comes to yarns that can be used for weaving, which use yet another measurement system. The issue with the Australian Ply system is that an individual ply of one thread can be finer than a 4-ply of another brand.

We get asked the question about ply vs other measurements regularly and would recommend you refer to the conversion table above. You can also look at the meters/100g of the yarn recommended in your pattern and compare for a similar measurement in other brands.

You are likely more familiar with yarn weight categories, such as worsted or DK weight, or numbers from 0 to 7. However, a more traditional way of measuring yarn weight is by wraps per inch.

Do remember that there is always going to be some variation with the different types of yarn. Yarn weights of different yarn types sit on a spectrum and do not fall into a single yarn weight category.

If you would like more information on understanding what the numbers in weaving yarns (ne 8/2, Ne 8/16) are, we would suggest you read the article 'Understanding Yarn Count in Weaving'.

As you enter the colourful world of craft, you'll be surprised to discover the plethora of yarns to choose from. Some are perfect for beginners, while others are more suited towards advanced crafters.

When it comes to crafts involving yarn, like knitting or crochet, knowing yarn standards makes all the difference. It helps you select the right needle or hook for your project, make yarn substitutions, and end up with results matching your vision.

Here at Thread Collective, we stock up on high-quality yarns from all over the world! We have yarns in many various weights, sizes, colours, and materials. Our website is designed to help you quickly select the perfect yarn for your next project. Browse our huge collection of yarns for your knitting, weaving, crocheting, and embroidery needs.