Yarn Weight Conversion Chart: Categories, WPI, and Hook Sizes
This chart covers the standard yarn weight categories from the Craft Yarn Council. Use it to substitute yarns, check gauge, or figure out what weight you have when the label is missing.
| Category | Name | WPI | Hook Size | Needle Size | Yards/100g |
|---|---|---|---|---|---|
| 0 | Lace | 30-40+ | 1.5-2.5mm | 1.5-2.25mm | 400-500 |
| 1 | Fingering/Sock | 18-30 | 2.5-3.5mm | 2.25-3.25mm | 350-450 |
| 2 | Sport | 14-18 | 3.5-4.5mm | 3.25-3.75mm | 250-350 |
| 3 | DK/Light Worsted | 12-14 | 4-5mm | 3.75-4.5mm | 200-300 |
| 4 | Worsted/Medium | 9-12 | 5-6mm | 4.5-5.5mm | 180-250 |
| 5 | Bulky/Chunky | 6-9 | 6-9mm | 5.5-8mm | 100-150 |
| 6 | Super Bulky | 4-6 | 9-15mm | 8-12mm | 60-100 |
| 7 | Jumbo | 1-4 | 15mm+ | 12mm+ | 30-60 |
How to Read This Chart
WPI stands for Wraps Per Inch. Wrap the yarn around a ruler without stretching. Count how many wraps fit in one inch. Use that number to find your category. The hook and needle sizes are starting points. Always swatch to match gauge.
Frequently Asked Questions
Is DK the same as sport weight?+
They're close but not identical. DK (Category 3) is slightly heavier than sport (Category 2). DK is about 12-14 WPI. Sport is 14-18 WPI. In a pinch, you can substitute one for the other, but swatch first.
Can I use two strands of DK to make worsted?+
Yes, approximately. Two strands of DK held together approximate worsted weight (Category 4). But always swatch. The gauge might not match exactly, and you'll need twice as many skeins.
What if my yarn doesn't have a label?+
Use the WPI method. Wrap the yarn around a ruler. Count wraps per inch. Match to the chart. You can also compare it to known yarns by holding them together and checking thickness.