Crochet Hook Conversion Chart {FREE Printable}

If you are just learning to crochet, one thing that may stump you is how to figure out which size crochet hooks to use.  It’s important to understand the various crochet hook sizes and which projects they are best used for.  A handy crochet hook conversion chart may be your go-to guide as you get acquainted with the wonderful world of crocheting.  Keep reading for more information on hook sizes and get my FREE crochet hook size chart…

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How do you know what size crochet hook to use?

When you start to crochet, it may be tempting to just grab any crochet hooks and any yarn and get to it.  You may think that hook and yarn sizes don’t matter much, as long as you like the color and texture of the yarn.  I find that we are often drawn to the beauty of crochet prior to working out the practical aspects, aren’t we?  😊

In addition, you may have purchased a crochet book or digital crochet pattern, then wondered how to interpret the ‘hook size’ you are instructed to use.  I know this can be especially daunting if the size is listed as a metric or US letter/number. 

How on earth can you decipher what they are asking if these terms are confusing? 

I find it helpful to have a crochet hook conversion chart on hand to understand the different terms used for the same hook.

Crochet Hook Size Chart

What are the crochet hook sizes?

The first thing you will need to understand about crochet hooks is that there are different ways to identify them if you are based in the United States (US size) or elsewhere, such as the United Kingdom (UK).

For example, the US crochet hook sizes have a combination of letters and numbers. These symbols run alphabetically & numerically, from smaller hooks to wider hooks (e.g. B-1 through S). 

The good news is that both US and other hooks can also be identified using metric numbers.  The crochet hook sizes in mm (“Metric”) distinguish the actual diameter of the shaft of the hook in millimeters (e.g. 2.25 mm through 19 mm).

Therefore, a useful crochet hook conversion chart will list both of these identifying letters/numbers so that you can interpret which size you need for a project. 

How many sizes of crochet hooks are there?

There are about 28 different sized hooks measured in mm (from 2.25 mm to 30 mm), and about 24 US sized hooks with symbols (within the same mm range).

CROCHET HOOK SIZE CHART PRINTABLE

I have this helpful FREE crochet hook size chart pdf to assist you in deciphering hook sizes.  If a crocheting pattern calls for a size in metric and you are used to US hook sizes, you can quickly scan the chart to determine the translation to US hook size.

On the other hand, if a crocheting pattern you want to try has US hook sizes listed and you always use metric sizes, the translation can work the other way.  You would use the crochet hook size chart mm to US translation.

Lastly, one more BONUS feature of this chart is that it also gives you the common YARN WEIGHT recommended for various groups of hook sizes.  Smaller hooks work best with lighter weight yarns, whereas wider hooks work best with heavier weight yarns.

You can find the chart in my CROCHET SUPPLIES CHEATSHEETS freebie for email subscribers:

This chart will help you answer a wealth of questions, such as those listed below…

CROCHETERS ASK: How do you convert crochet hook sizes? 

When you are new to crocheting, you may find all the various crochet hook sizes confusing. Here are some great beginner crocheter questions that I hope will help you along your crochet journey.

First, questions on how to read this free chart – 

What size is a 4 mm crochet hook?

Here’s an example – a pattern calls for a 4 mm crochet hook, and you want to know if you already own this size as part of your US hook collection.  Simply locate the 4 mm under the ‘Metric’ column on the chart, then look in the next column under ‘US’ size numbers and you will find the symbol G-6. Hopefully the manufacturer of the hook labeled the hook with both the US size and Metric size, but the US size may be more familiar to you.

What is a size H crochet hook? How many mm is a size H crochet hook?

A pattern may call for a size H crochet hook to be used in the project.  Perhaps you are used to Metric sized hooks and don’t know which size this is.  Sometimes alphabetic letters are referenced in a pattern without a corresponding number.  You will notice that there is a H-8 size listed under the ‘US’ column on the chart.  This is the only ‘H’ size.  Next, look in the corresponding column under ‘Metric’ size numbers and you will find the size 5 mm.

Next, some questions on the best hooks for beginners – 

What is the best crochet hook for beginners? 

In general, the best size crochet hook for beginners is H-8 (5 mm).  This size is near the middle of the conversion chart and works best with ‘Light’ or ‘Medium’ yarn weight (aka ‘worsted’ weight yarn).  When you are just starting out trying to crochet stitches, you don’t want to struggle with tiny yarn and hooks. You also don’t want to wrestle with jumbo yarn with huge hooks.

I found this inexpensive BEGINNER FRIENDLY CROCHET HOOK SET with common sizes:

What is the best size crochet hook? 

I think the answer to this question may vary for each person, but the most commonly used crochet hooks are sizes 4.5 mm to 6 mm.  These hooks can be used with the most common yarn weight, ‘Medium’ (aka ‘worsted’), and are easy to manage. 

What type of crochet hook is best? 

Crochet hooks also come in various configurations and materials for each size.  Aluminum, wood, and plastic are common materials for hooks. I would suggest you try a variety of hook materials & configurations before you decide on what feels most comfortable.  These days, manufacturers also offer ergonomic crochet hooks that may be easier to use.   

As far as hook configurations, the two basic shapes for crochet hook ‘heads’ are Inline and Tapered. The heads are the top of the hook, which is the part that grasps the yarn while you are working.

Inline Crochet Hooks

INLINE CROCHET HOOKS have a pointy ‘head’ at the top, which is the same size as the ‘shaft’ below it. For instance, here are some examples of inline crochet hooks: 

Tapered Crochet Hooks

TAPERED CROCHET HOOKS, however, have a more rounded ‘head’ at the top of the hook. The ‘throat’ just beneath the head is also thinner than the ‘shaft’ below.

Here are examples of tapered crochet hooks:

How do I know my crochet hook size? 

You may also be in a circumstance where you own crochet hooks (passed down from your sweet grandmother?) that do not indicate a size.  Perhaps the writing on the hook itself has worn off or is too difficult to decipher.  

There is a way you can determine the size of a crochet hook in hand – use a CROCHET HOOK GAUGE TOOL!   These handy dandy gauge tools come in a variety of materials and styles.  Each gauge tool has openings that you can slide your hook through.  The opening that matches the exact fit of the diameter of your hook will indicate the size of that hook.  This is so helpful!

Crochet patterns and Crochet hooks 

You may also be wondering, what crochet hooks are best for which projects?  As you can see from the free printable conversion chart, crochet hooks in the smaller mm diameter (2.25 – 4.5 mm) are best used for superfine and fine weight yarn projects.  Examples of these are socks, lacy shawls, and baby attire/accessories. 

Moving up the size chart, the best projects for 5mm to 6.5 mm hooks are those using Light or Medium weight yarn (aka ‘worsted’).  You will find a plethora of patterns using these size hooks for common projects like hats, sweaters, mittens, scarves, wraps, home goods, etc. 

What size crochet hook to use for big projects? Large sized hooks are best for rugs and large blankets or pillows, made with super bulky and jumbo sized yarn. These sized hooks can range in sizes L-11 (8 mm) through S (19 mm). What is the largest size crochet hook? T (30 mm) is the biggest!

A note about steel crochet hooks: I did not include steel crochet hook sizes on my crochet hook conversion chart, as they are dedicated to a specific crochet hobby.  These tiny hooks are generally sized from 1.6-1.4 mm in metric, and 6-8 in US.  They are designed for crochet LACE work (such as doilies), using very thin crochet thread (yarn weight size 0).  This type of crochet work is not recommended for beginners, but feel free to pursue these intricate projects down the road.      

I offer quite a few beginner-friendly crocheting patterns such as these…

Final Thoughts about CROCHET HOOKS

I hope my free printable for a crochet hook conversion chart will help you navigate the choices for various size hooks.  It is my genuine desire to be a cheerleader for beginner crocheters. Any time I can reduce any confusion is a welcome opportunity. 

I would love to hear if this crochet hooks size chart has helped you – let me know in the comments!

If you are interested in learning more about crochet supplies, check out my LIST OF CROCHET ESSENTIALS.

Visit the CROCHETING category on my blog or ETSY SHOP to find more crocheting goodies!

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