Yarn Weight Converter
Convert between yarn weight systems.
Compare US, UK, and Australian yarn weights with needle sizes and gauge recommendations.
Yarn Weight Information
Yarn weight categories are standardized by the Craft Yarn Council (CYC) to help knitters and crocheters substitute yarns and interpret patterns from different countries. Weight refers to thickness, not mass.
CYC Standard Weight System (0–7 scale):
| CYC # | Name | Wraps per inch | Knit gauge (4") | Common uses |
|---|---|---|---|---|
| 0 | Lace | 40+ wpi | 32–42 sts | Shawls, doilies |
| 1 | Super Fine | 32–40 wpi | 27–32 sts | Socks, baby items |
| 2 | Fine | 26–32 wpi | 23–26 sts | Light garments |
| 3 | Light | 21–26 wpi | 21–24 sts | DK weight projects |
| 4 | Medium | 14–20 wpi | 16–20 sts | Sweaters, hats |
| 5 | Bulky | 12–15 wpi | 12–15 sts | Blankets, scarves |
| 6 | Super Bulky | 7–11 wpi | 7–11 sts | Quick blankets |
| 7 | Jumbo | 1–6 wpi | 6 or fewer | Arm knitting |
Wraps Per Inch (WPI) — universal thickness test:
Wrap yarn around a ruler for 1 inch, count wraps → WPI
Cross-system equivalents:
| CYC Name | UK Name | Australia |
|---|---|---|
| Super Fine (1) | 2-ply / 3-ply | 3-ply |
| Light (3) | DK | 8-ply |
| Medium (4) | Aran | 10-ply |
| Bulky (5) | Chunky | 12-ply |
Needle/hook size conversion:
- CYC 4 (Medium/Worsted): US 7–9 needles (4.5–5.5mm)
- CYC 5 (Bulky): US 10–11 needles (6–8mm)
- CYC 6 (Super Bulky): US 13–17 needles (9–12mm)
Gauge swatch rule: Always knit a 4"×4" swatch before starting any project. Gauge trumps the suggested needle size — adjust until your stitch count matches the pattern.