Yarn weight numbers 0 through 6, printed on most yarn labels, correspond to a fairly predictable crochet hook size range. I use this numbering as my quickest lookup when a pattern only lists the weight category and not a specific hook.
Weight number to hook size
- 0, lace: 1.5mm to 2.25mm.
- 1-2, fingering to sport: 2.25mm to 3.25mm.
- 3, DK: 3.5mm to 4.0mm.
- 4, worsted: 5.0mm to 5.5mm.
- 5, bulky: 6.5mm to 9mm.
- 6, super bulky: 9mm and up.
Why I check the label’s actual suggestion too
The weight number gives a range, but the yarn label itself usually prints a more specific suggested hook, and I check both before starting a new skein I haven’t used before.
Frequently asked questions
What does the yarn weight number mean?
It’s a standardized category from 0 (lace) to 6 (super bulky) describing how thick the yarn strand is, which determines the general hook size range that suits it.
Where do I find the yarn weight number on a skein?
Most labels print a small yarn-strand icon with a number from 0 to 6 inside it, usually near the suggested hook or needle size.
See the full hook, letter, and UK size chart
Cross-reference every size system in one table.