Crochet Hook Sizes & A Handy Conversion Chart

There was such a good response to the knitting needle size conversion chart that it seemed like a crochet chart was in order too! While crochet hooks use letters instead of numbers to differentiate sizes in the US, they use good old (and arguably less confusing) millimeters elsewhere to tell sizes apart. Since it’s hard to remember that an H hook is equivalent to 5 mm right off the top of your head, the chart below is a good one to bookmark or pin for future reference.

Crochet Hook Conversion Chart

a.k.a. What size is my crochet hook? 

Important notes

• All listed hook sizes are based on the Craft Yarn Council’s standards, an organization worth bookmarking for all needlearts lovers! It’s important to note that there can be some inconsistency among crochet hook brands, which I noted with my knitting needles conversion chart too. Because of issues like this, I recommend always double checking your hook size using a measuring tool that includes both US and mm sizes. When designing crochet projects, I also recommend always deferring to mm sizing because it’s an objective standard of measurement. You can never be too careful with gauge!
• For consistency’s sake, this post was intentionally formatted the same way as the knitting needle version of this post. :)