You've found the perfect yarn — now which hook? Crochet hooks come in dozens of sizes, several naming systems and a surprising variety of materials. This guide explains hook sizes, how to convert between US letters and millimeters, and how to choose a hook that's kind to your hands.
Anatomy of a crochet hook
- Head/tip: the part that goes into the stitch. Pointy tips slide into tight stitches easily (great for amigurumi); rounded tips are less likely to split yarn.
- Throat: the groove that catches the yarn. Inline hooks have a throat level with the shaft; tapered hooks have a sloped throat. Many crocheters strongly prefer one or the other — try both!
- Shaft: this determines the size of your loops, and therefore the hook size.
- Grip/handle: where your thumb rests. Ergonomic handles are thicker and softer.
Hook size conversion chart
Millimeters are the most reliable measure — US letter sizes can vary slightly between brands. When in doubt, go by mm.
| Metric (mm) | US | Old UK/Canada | Common yarn |
|---|---|---|---|
| 2.25 | B-1 | 13 | Fingering / fine amigurumi |
| 2.75 | C-2 | 12 | Fingering, sport |
| 3.25 | D-3 | 10 | Sport, DK amigurumi |
| 3.5 | E-4 | 9 | Sport, DK |
| 3.75 | F-5 | — | DK |
| 4.0 | G-6 | 8 | DK, light worsted |
| 5.0 | H-8 | 6 | Worsted |
| 5.5 | I-9 | 5 | Worsted, aran |
| 6.0 | J-10 | 4 | Aran, chunky |
| 6.5 | K-10½ | 3 | Chunky |
| 8.0 | L-11 | 0 | Bulky |
| 9.0 | M/N-13 | 00 | Super bulky |
| 10.0 | N/P-15 | 000 | Super bulky, blanket yarn |
Steel hooks for thread use a separate numbering system where larger numbers mean smaller hooks — check the mm size on the package.
How to choose the right size
- Start with the yarn label. It lists a recommended hook size for general fabric.
-
Adjust for the project.
- Amigurumi and toys: go 0.5–1.5 mm smaller for tight, stuffing-proof fabric.
- Blankets, shawls and anything drapey: stay at or go slightly larger.
- Adjust for your tension. If your fabric is stiff and hard to work, size up. If it's loose and holey, size down.
- Follow the pattern when you want to match the designer's finished size — but treat it as a starting point, not a rule.
Hook materials compared
| Material | Feel | Good for |
|---|---|---|
| Aluminum | Smooth and fast, lightweight, affordable | Most yarns, everyday use |
| Steel | Very fine and strong | Thread crochet, lace |
| Bamboo / wood | Warm, a little "grippy" | Slippery yarns, people who like a slower pace |
| Plastic / acrylic | Light, often large sizes | Bulky and blanket yarns |
| Ergonomic (soft handle) | Thick, cushioned grip | Long sessions, sore hands or wrists |
Why ergonomic hooks are worth it
Crochet is a repetitive motion. Holding a thin metal hook for hours can cause hand cramps and wrist strain. Ergonomic hooks spread the pressure across a wider, softer handle, letting you crochet longer and more comfortably. If you crochet more than a few hours a week, a good ergonomic hook set is one of the best investments you can make.
Beginner starter recommendations
- Just one hook? A 5.0 mm (H-8) with medium/worsted yarn is the classic beginner combo.
- Want to make amigurumi? Add 2.5 mm, 3.0 mm and 3.5 mm hooks.
- Want flexibility? A set with sizes from 2.0 mm to 6.0 mm (or larger) covers almost every pattern — and usually costs less than buying hooks one by one.
Caring for your hooks
Store hooks in a case or roll so the tips don't get scratched (a scratched hook snags yarn). Wipe them occasionally to remove oil and fuzz, and keep wooden hooks away from moisture. A simple storage organizer also means you'll never lose your favorite size again.
Pair your hook with the right yarn using our yarn guide, and you're ready to start one of our free patterns.
Happy stitching from the DanSan Crochet team! 🧶