Crochet Hook Size Chart

Ever picked up a vintage pattern or a gorgeous skein of yarn and wondered exactly which hook size you need? 🧶✨ Welcome back to the Library on the Laine! Hook sizing can get a little tricky when patterns bounce between metric millimeters, U.S. letters, and U.S. numbers. To make your project planning a total breeze, I’ve put together this complete, easy-to-read crochet hook conversion guide. Whether you are hunting down a classic Size H hook or sizing up for chunky yarn, this chart has your stitches covered. Scroll down to look at the chart or print a free copy for your craft room!

Crochet hook size conversion chart mm to US letters and numbers - free printable guide by Daisy Laine Boutique
💡 Stephanie's Tips for Perfect Gauge & Hook Selection:
  • Trust the Millimeters: Because letter and number sizing can slightly vary from company to company, always rely on the accurate metric millimeter (mm) sizing printed on your hook handle or package for the most consistent results.
  • Never Skip the Gauge Swatch! Before diving headfirst into a brand-new blanket or sweater pattern, always stitch up a quick gauge swatch. If your finished swatch is too small, switch over to a larger hook to reach the pattern's gauge. If your swatch is too big, slide down to a smaller hook.
  • Keep it Untangled: Working with massive, chunky hooks or delicate steel ones? Keep your favorite tools clean, organized, and perfectly contained in our custom 3D-printed craft room organizers!

Need to double-check another size guide or abbreviation sheet? Head right back over to the main Library on the Laine Hub to keep exploring! Before you grab your hook and run off to start that next gauge swatch, make sure your project has plenty of gorgeous yarn bling to keep you company. Explore our 3D Printed Yarn Bowls and handmade goodies to keep your craft space beautiful and happy. Happy stitching! 🌸

🔍 Quick Searchable Crochet Hook Directory
Can't read the image above clearly or want to use Ctrl+F to find a size fast? Here is our text-based conversion directory!
Metric / mm U.S. Letter U.S. Number
2.25 mm B 1
2.50 mm — —
2.75 mm C 2
3.125 mm D —
3.25 mm D 3
3.50 mm E 4
3.75 mm F 5
4 mm G 6
4.25 mm G —
4.50 mm — 7
5 mm H 8
5.25 mm I —
5.50 mm I 9
5.75 mm J —
6 mm J 10
6.50 mm K 10.5
7 mm — —
8 mm L 11
9 mm M/N 13
10 mm N/P 15
11.50 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 —