Yarn Weight Systems Explained
Yarn weight describes the thickness of yarn. Unfortunately, different countries use different naming conventions. US patterns use names like "worsted" and "bulky," UK patterns use "aran" and "chunky," and Australian patterns use ply numbers. The CYC (Craft Yarn Council) number system (0-7) attempts to standardize this, but many patterns still use regional names.
Complete Yarn Weight Comparison
| CYC # | US Name | UK Name | AU Name | WPI |
|---|---|---|---|---|
| 0 | Lace | 1 ply / Cobweb | 1 ply | 30+ |
| 1 | Fingering / Sock | 3 ply / 4 ply | 3-4 ply | 14-20 |
| 2 | Sport / Baby | 5 ply | 5 ply | 12-14 |
| 3 | DK / Light Worsted | DK / 8 ply | 8 ply | 11-12 |
| 4 | Worsted / Afghan | Aran / 10 ply | 10 ply | 9-11 |
| 5 | Bulky / Chunky | Chunky / 12 ply | 12 ply | 7-8 |
| 6 | Super Bulky / Roving | Super Chunky | 14 ply | 5-6 |
| 7 | Jumbo | Mega Chunky | Mega chunky | 1-4 |
What Is WPI (Wraps Per Inch)?
WPI is the most objective way to measure yarn weight. Wrap yarn around a ruler or WPI tool snugly (not stretched, not loose) and count how many wraps fit in one inch. More wraps = thinner yarn. This method works regardless of what the label says and is especially useful for handspun, unlabeled, or mystery yarn.
Yardage per 100g by Weight
| Yarn Weight | Yards per 100g | Meters per 100g |
|---|---|---|
| Lace | 800-1,200 | 730-1,100 |
| Fingering | 350-500 | 320-460 |
| Sport | 250-350 | 230-320 |
| DK | 220-280 | 200-255 |
| Worsted | 180-220 | 165-200 |
| Bulky | 100-150 | 90-137 |
| Super Bulky | 60-100 | 55-90 |
| Jumbo | 20-60 | 18-55 |
FAQ
Is DK the same as worsted?
No. DK (CYC #3) is thinner than worsted (CYC #4). DK typically knits at 21-24 stitches per 4 inches, while worsted knits at 16-20 stitches. In UK patterns, "DK" is sometimes called "8 ply," and what Americans call "worsted" is called "Aran" or "10 ply" in the UK.
What does "ply" mean in Australian yarn?
In Australia (and the UK), "ply" is used as a weight category, not a literal count of strands. "8 ply" means DK weight regardless of how many actual plies the yarn has. A yarn could be a single strand (1 ply construction) but still be labeled "8 ply" if it matches DK weight thickness.
Can I substitute yarn weights in a pattern?
Going one weight up or down is sometimes possible if you adjust needle size and swatch to match the pattern gauge. Going two or more weights away will change the fabric drape, stitch definition, and yardage requirements significantly. Always swatch when substituting.
Related Tools
- Yarn Yardage Calculator — how much yarn to buy for any project
- Knitting Needle Size Converter — recommended needles per yarn weight
- Crochet Hook Size Converter — recommended hooks per yarn weight
- Knitting Gauge Calculator — expected gauge for your yarn weight