Crochet Hook Size Chart
Complete crochet hook size conversion chart with US letter/number, Metric (mm), and UK sizes. Includes recommended yarn weights for each hook size.
| US Letter / Number | Metric (mm) | UK Size | Yarn Weight |
|---|---|---|---|
| B/1 | 2.25 | 13 | Lace / Fingering |
| C/2 | 2.75 | 12 | Fingering / Sport |
| D/3 | 3.25 | 10 | Sport / DK |
| E/4 | 3.5 | 9 | DK |
| F/5 | 3.75 | - | DK |
| G/6 | 4 | 8 | DK / Worsted |
| 7 | 4.5 | 7 | Worsted |
| H/8 | 5 | 6 | Worsted / Aran |
| I/9 | 5.5 | 5 | Aran |
| J/10 | 6 | 4 | Aran / Chunky |
| K/10.5 | 6.5 | 3 | Chunky |
| L/11 | 8 | 0 | Bulky |
| M/13 | 9 | 00 | Bulky |
| N/15 | 10 | 000 | Super Bulky |
| P/16 | 11.5 | - | Super Bulky |
| Q | 15 | - | Jumbo |
| S | 19 | - | Jumbo |
How to Read This Chart
Find your pattern’s recommended hook size in any column and look across the row to find the equivalent in other sizing systems. The metric (mm) measurement is the actual diameter of the hook shaft and is the most reliable way to match hook sizes across brands.
Frequently Asked Questions
What size crochet hook should a beginner use?
Beginners should start with a US H/8 (5.0 mm) hook. It is a comfortable middle size that pairs well with worsted weight yarn, which is the easiest to work with when learning.
How do I convert US crochet hook sizes to metric?
US crochet hook sizes use letters and numbers that correspond to specific mm measurements. For example, G/6 = 4.0 mm, H/8 = 5.0 mm, and J/10 = 6.0 mm. See the chart above for all conversions.
Are crochet hooks and knitting needles the same sizes?
Crochet hooks and knitting needles share the same metric (mm) sizes but use different US naming systems. Crochet hooks use letters (B through S), while knitting needles use numbers (0 through 50). A 5.0 mm hook (H/8) is the same diameter as a 5.0 mm knitting needle (US 8).
What is the difference between inline and tapered crochet hooks?
Inline hooks (like Susan Bates) have a consistent shaft diameter with a pointy tip, while tapered hooks (like Boye) gradually narrow toward the tip. The size listed on the hook refers to the shaft diameter in both cases. Choose based on personal grip comfort.