Craft Yarn Council yarn weight standards
Key takeaway: CYC labels yarn categories 0 (Lace) through 7 (Jumbo)—category 4 (worsted / medium) is the default in most FiberCalc yarn tools, including the ~1,815 yd throw example. Use the category number on the ball band when estimating yardage.
The table below summarizes publicly documented CYC ranges plus FiberCalc planning midpoints for yards per 100 g (site heuristic for substitution math—not a CYC publication). Always confirm the icon and gauge on your specific yarn band—brand naming (especially “DK” vs “worsted”) can vary.
| # | Name | WPI | Knit sts/4″ | Needles mm | Crochet sts/4″ | Hooks mm | yd/100 g (mid) |
|---|---|---|---|---|---|---|---|
| 0 | Lace | 30–40+ | 33–40 | 1.5–2.25 | 32–42 dc | 1.4–2.25 | 766 |
| 1 | Super Fine | 14–30 | 27–32 | 2.25–3.25 | 21–32 sc | 2.25–3.5 | 438 |
| 2 | Fine | 12–18 | 23–26 | 3.25–3.75 | 16–20 sc | 3.5–4.5 | 345 |
| 3 | Light | 11–15 | 21–24 | 3.75–4.5 | 12–17 sc | 4.5–5.5 | 263 |
| 4 | Medium | 9–12 | 16–20 | 4.5–5.5 | 11–14 sc | 5.5–6.5 | 208 |
| 5 | Bulky | 6–9 | 12–15 | 5.5–8 | 8–11 sc | 6.5–9 | 142 |
| 6 | Super Bulky | 5–6 | 7–11 | 8–12.75 | 7–9 sc | 9–15 | 88 |
| 7 | Jumbo | 1–4 | 1–6 | 12.75–25 | 1–6 sc | 15–25 | 44 |
CYC lists category 0 crochet gauge in double crochet; categories 1–7 use single crochet. Lace WPI is published as 30–40+ wraps. Jumbo knit/crochet gauges are “6 sts and fewer,” encoded here as 1–6 for a closed table range.
How to use this chart with FiberCalc
Match the CYC icon on the ball band to the “#” column, then enter that weight in a yarn calculator. The yd/100 g midpoint feeds the yarn substitution calculator when a skein omits length. Project densities (yards per square inch) live on Methodology—they are FiberCalc heuristics, not CYC figures.
Typical projects by category
- 0–2 — lace shawls, socks, fine baby garments
- 3–4 — sweaters, blankets, hats, amigurumi (DK/worsted defaults)
- 5–7 — quick throws, chunky cowls, arm-knit statement pieces
Sources
- Craft Yarn Council — Standard Yarn Weight System (checked 2026-11-07)
- Craft Yarn Council — How to measure wraps per inch (WPI) (checked 2026-11-07)
- Craft Yarn Council — Hooks & Needles (checked 2026-11-07)
- FiberCalc methodology — yarn density factors (site heuristic)
Related: yarn substitution calculator, needle & hook converter, yarn substitution basics, hook size conversion chart, blanket yarn guide, sweater yarn guide, amigurumi yarn guide.