Take the guesswork out of crochet hook sizes with this comprehensive Crochet Hook Sizes Conversion Chart. Learn how to navigate between Metric, US, UK and Japanese crochet hook sizing terms. This guide will empower you to choose the right hook size for any pattern with confidence. You can even download and print the quick reference chart so you’ll never feel overwhelmed by hook sizes again!

A, B, C … 1, 2, 3. Does finding the right crochet hook size ever make you feel like you’re back in Kindergarten again? I can smell the crayons and feel my scratchy nap-time beach towel beneath me! (PS – who has a Kindergartener that STILL TAKES NAPS?)

Are you tired of feeling lost in a sea of crochet hook sizes? Look no further for clarity and confidence in your next project. In this ultimate guide and printable crochet hook sizes conversion chart, I will break down the terminology, show you how to convert between different sizing systems, and provide practical tips for choosing the right hook for your project. Say goodbye to confusion and hello to creativity as we dive into the world of crochet hook sizes!

Understanding Crochet Hook Sizes Terminology

You may or may not already know about my mild obsession with crochet hooks. I believe that becoming an expert in understanding crochet hooks is certainly worthy of some type of advanced certification. If you want to consider yourself CERTIFIABLY PRO in the study of the crochet hook, be sure to download my free Ultimate Guide to Crochet Hooks in the Resource Library. You will never have another question about this most revered crochet tool.

Before we delve into the specifics of converting all the crochet hook sizes, it’s important to understand the terminology used to describe crochet hooks. When it comes to crochet hooks, the size is often indicated by a letter, number, or millimeter measurement. The most common sizing systems are the US system, which uses letters (e.g., A, B, C), and the metric system, which uses millimeters (e.g., 2.25mm, 5mm). Additionally, some countries may use their own sizing system, so it’s beneficial to familiarize yourself with these variations to ensure you select the correct hook for your project. By grasping the terminology associated with crochet hook sizes, you can navigate between different sizing systems with ease and confidence.

Now, let’s get to the good stuff… how to convert crochet hook sizes from between Metric, US, UK and Japanese terminology.

The Ultimate Conversion Chart You Need

I’m 99% sure you won’t ever have to take a test on your crochet hook conversion knowledge. But if you ever do, I hope it’s open book. So, I have created a Crochet Hook Sizes Conversion Chart downloadable quick reference card so you will never have to worry about this again.

This conversion chart includes metric sizes from 0.75 mm through 19.00 mm and includes conversions for METRIC, US, UK and JAPAN. I mean, COME ON – the art of Amigurumi was ROOTED in Japan – they certainly deserve to be represented on a common crochet hook conversion chart. Can I get an AMEN?

I’m sorry if you’re one of the few that uses a crochet hook smaller than 0.75 mm. You have eyes like the owl and you are my hero. I didn’t include those sizes on my chart and they only include 6 hooks sized only for Metric and Japan. Just for you, here they are:

Metric to Japanese Steel Hook Size Conversions:

METRIC / JAPAN
0.40mm / 24-lace
0.45mm / 23-lace
0.50mm / 14-lace
0.55mm / 13-lace
0.60mm / 12-lace
0.70mm / 11-lace

You’re welcome.

So, without further ado, here is your Crochet Hook Sizes Conversion Chart. You can view it here, or you can download and print it from the Resource Library here.

The downloadable conversion chart in the Resource Library is an 8.5″ x 11″ size in full color. Many have wanted the chart in smaller sizes to keep with their crochet hooks or to have on the go. So, I decided to create a more robust PDF packet with 5 sizes and available in both color and black and white. You can find the full packet with all sizes and both color options in my Etsy shop for a small fee.

The smaller wallet sized ones are great to laminate and keep with you in your crochet hook case!

Choosing the right crochet hook size for your project will ultimately depend on the pattern requirements and your own preferences as a crocheter. But now, if your pattern calls for a 5.50mm crochet hook (Metric terminology) but you’ve only ever used US terminology before, you can refer to this chart and confidently pick up your size I hook and carry on.

In this article, I have equipped you with everything you need to know about understanding the terminology and conversions between different crochet hook sizing systems. Now, you can choose the right hook size with ease. As you dive into your next project, let this guide be your trusted companion in the world of crochet hook size conversions!