Skip to main content

Understanding Yarn Weight, Crochet Hook Size and Yarn Gauge

Types of Yarn

Even though I’ve been crocheting for more than 12 years I still have to remind myself about yarn weight, crochet hook size and yarn gauge as it relates to a particular project. If you are mainly self taught, like I am, you may not have been taught this aspect of design.

Basically the outcome of your garment is determined by 3 things – the size of your crochet hook, the weight of your yarn and your gauge or how tightly or loosely you make your stitches.

When you purchase a ball or skein of yarn you will see a symbol with a number on it. This number is the Yarn weight and ranges from 1 – 6.

Determining Gauge


Categories of Yarn

  1. Superfine – This is your sock yarn, your fingering yarn and your baby yarn. You’ll see it identified as number 1. It is thin and is perfect for things like shawls, socks and delicate baby items. The suggested crochet hook for this yarn is a U.S. B1 – E4 or metric size 2.25mm – 3.5mm. When you make a gauge, which is usually a 4 inch by 4 inch square, it should have between 21 and 32 stitches across.
  2. Fine – This is the next size up – a number 2 – and again it is a thin yarn, this is your sport and baby weight yarns. This type of yarn is good for baby items, sweaters, accessories, and wraps. You’ll want to use a U.S. hook size E4 – 7 or metric size 3.5mm – 4.5mm. The gauge you want to shoot for is between 16 and 20 stitches across.
  3. Light – DK and light worsted yarns fall under this category - a number 3 on your label - and is used it all sorts of projects along with its counterpart Medium which we’ll discuss later. This yarn can be used in a number garments likes hats, fingerless gloves, sweaters and even for heavier baby blankets. Crochet hooks for this yarn are U.S. 7 – 19 or metric size 4.5mm – 5.5mm. Gauge for this type of yarn is usually about 12 stitches to 17 stitches across.
  4. Medium – This yarn is commonly used in blankets, crafts, slippers and sweaters and is known as a number 4. Some crocheters use this yarn exclusively. It is known as worsted, Afghan, and Aran yarn. Common hook sizes for this type of yarn is U.S. size 19 to size K or 10 ½. The metric standard size hook is 5.5mm to 6.5mm. The gauge recommendation for this yarn is about 11 stitches to about 14 stitches across.
  5. Bulky – Chunky, craft and rug yarn are a number 5 and fall under this category. It is used to make rugs and thick blankets. Some use this yarn for doll hair or in unique scarves and hats. It’s also a good yarn for decorating with. Your crochet hook is larger anywhere between a U.S. K (10 ½) to an M or a 6.5mm – 9mm in metric standard. You’ll find that your projects work up a bit faster with this type of yarn because you’ll get anywhere between 8 stitches to 11 stitches across in your 4 x 4 gauge swatch.
  6. Super Bulky – This is a number 6 and Roving and super chunky yarns are in this category. Use a crochet hook size M or larger when working with this yarn. For metric standard that is a size 9mm or larger. This is the type of yarn is used in huge rug projects like the famous doily rug that is so popular right now. You can use this yarn for doll hair as well and it is a great yarn to teach little hands how to finger knit. The gauge for super bulky yarn is between 5 stitches and 9 stitches across. This is definitely the way to go if you want to crochet a project quickly.

Worsted Weight Yarn

The Relationship of Yarn, Hook and Gauge

Now that you know more about how your yarn, hook and gauge work within your project you’ll be able to plan accordingly. This helps you in deciding the type of yarn to use for a particular garment as well as how much yarn you need to buy. If you find a yarn that you really like, work up swatches in a number of hook sizes and keep them in your design folder. This way you don’t have to go through the process each time you make a new project.

The more you work with yarn and the longer you crochet the easier this all becomes. You’ll be able to estimate your gauge just by looking at the yarn. It is still advised to work your stitch pattern into a swatch though so that no surprises come up.

Additional Lessons in Yarn Weight

Learning Crochet With Mom

Learn the Little Scallops

Learn the Little Scallops

About Sara Duggan

I'm a wife and Mom of 2. I enjoy writing and crochet. I've found a way to merge the two with article marketing and blogging. Interested in learning more about crochet? Visit Crochet with Mom for Lessons and tips

Do You Understand the Difference in Yarns and Hooks?

Beverly on October 23, 2013:

This is very helpful. Since I live in Florida and don't need the worsted weight yarn for hats, but would prefer to make the sport weight, how can I make the changes and still come out with the sizes needed?

Sara Duggan (author) from California on March 25, 2012:

Scroll to Continue

@Jackie, Yes I know. When I first started yarn was yarn.

Sara Duggan (author) from California on March 25, 2012:

Yes it is. It is especially useful when you start designing your own items.

Jackie on March 25, 2012:

wow. I had no idea about the different kinds of yarns. Thanks so much for the excellent information!

Helena Reimer on March 25, 2012:

This is excellent information...and a handy reference to keep around.

Sara Duggan (author) from California on March 24, 2012:

Thank you.

Sara Duggan (author) from California on March 24, 2012:

Thank you. It is definitely useful to know - I wish I learned all this when I started to crochet.

MsRocmama on March 24, 2012:

I love this very imformative

Angelo52 on March 24, 2012:

I do not crochet but if I did this would have to be an article to read. Voted up and shared to face book.

Related Articles