What Are The Sizes of Crochet Hooks?

If you’re new to crocheting, you’ll have a wealth of information to get to grips with.

Crochet hooks can be one of the most confusing things for beginners to learn – before you start, you might not realize there are so many different sizes to choose from.

What Are The Sizes of Crochet Hooks

Choosing the right hook can make or break your project, so choosing the right size is crucial. 

If you’re still figuring out the big wide world of crochet hooks, don’t worry! In this post, we’re going to guide you through our comprehensive hook size guide, and show you how to use each hook – the right way.

Whether you’re an experienced crocheter or a complete beginner, stick around to learn some of the most important crochet tips EVER.

Crochet Hook Size Guide 101 

Before we start introducing you to these different crochet hooks, let’s go back to basics. 

The size of your crochet hook will correlate with certain weights of yarn.

If you’re crafting your crochet creation from a specific pattern, you’ll usually be told which hook size suits your yarn weight, so you can recreate the same look and feel you see in the pictures.

Most yarn labels will also list a range of hook sizes that correspond with their weight, so you can figure out which hooks work best with that exact yarn. 

If you’re in the US, crochet hooks will be measured in letters, (see also: How To Crochet Letters (Monogram Crochet))and in the UK, they’ll be measured in metric units.

Crochet hooks have evolved across continents, so you may see different units of measurement elsewhere, too.

However, most yarn labels will include both the US and UK forms of hook measurement. 

Most crochet hooks range between size B1 (2.25mm) and T/X (30mm). If you ever need to convert hook sizes, check out our handy guide below. 

UK (mm) US (letter)
2.25 mm B-1
2.5 mm – 
2.75 mm C-2
3.125 mm D
3.25 mm D-3
3.5 mm E-4
3.75 mm F-5
4 mm G-6
4.25 mm G
4.5 mm 7
5 mm H-8
5.25 mm I
5.5 mm I-9
5.75 mm J
6 mm J-10
6.5 mm K-10 ½ 
7 mm – 
8 mm L-11
9 mm M/N-13
10 mm N/P-15
11.5 mm P-16
12 mm 
15 mm P/Q
15.75 mm Q
16 mm Q
19 mm S
25 mm T/U/X
30 mm T/X

How Do I Know Which Crochet Hook to Use? 

How Do I Know Which Crochet Hook to Use 

In general, most larger hooks are used with thicker yarns, and smaller hooks with thinner yarns.

Most crochet yarns will list a selection of appropriate hooks on their labels, so you’ll know which ones will work best for your project.

Yarn labels will also list more general information about the product, including its fiber content. 

If you’re following a pattern, the designer will usually list the appropriate hook sizes for you, so you won’t have to play a guessing game yourself.

This guidance will ensure that your end result looks like the designer’s, so try not to change the gauge of your hook unless you absolutely have to. 

What Is A Gauge Swatch? 

When you’re exploring patterns and different hook sizes, you’ll probably come across the term ‘gauge swatch’. 

A gauge swatch is essentially a simple knitted or crocheted square of fabric that shows how you’ll need to use your fabric and hooks to create the final project.

Crochet gauge swatches are usually between 12.5cm and 5 inches square, and they’ll be made in exactly the same stitch as your desired crochet pattern. 

Whether you’re a beginner or an experienced crocheter, we’d always recommend making a gauge swatch before starting work on your main project.

It’s a sure-fire way to set you up for success, and ensure you’re ‘meeting gauge’ (aka, following the measurements of the designer). 

How To Make A Gauge Swatch 

If you’re working with thicker yarn, your swatch may need to be larger than the recommended size. Bare this in mind before you start making your swatch. 

There are a few ways to start making your gauge swatch. Some patterns may provide exact gauge instructions, while others won’t.

We’d recommend starting your first (or foundation) row at a measurement of between 12-15 cm.

From here, you can work with the stitch pattern you’ve been given until you’ve created a large enough swatch to take measurements from. 

If you haven’t been given a stitch pattern, examine the overall pattern and see if there’s a dominant stitch being used that you can identify. Establishing the dominant stitch will help you work out what exactly the gauge is referring to. 

How Does Hook Size Affect Crochet? 

If you’re trying to crochet a fabric, you’ll need your hook and yarn to work together in tandem. Larger hooks will make your projects larger, while small hooks will make them smaller.

Larger hooks will also provide looser stitches, giving you fabric more of an ‘overhang’ or a drape. With a smaller hook, you’ll create much tighter stitches that will give your final fabric more density.

So, whether you’re creating an item of clothing, a stuffed animal, or something else, you’ll need to choose the right hook size to get the final result right. 

The Bottom Line 

When you first start crocheting, there’s a lot to consider. Not only do you have to master the actual art of crocheting (which can be pretty tough for beginners!), but you also have to understand how your yarn and hooks affect the final outcome of your project. 

Knowing the hook sizes and understanding how they work is one of the most important things you’ll need to know.

We hope that this post has offered a gentle introduction into the world of crochet hook sizes – with a little practice and patience, you’ll be well on your way to creating a true crocheted work of art! 

Nancy Adriane
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