Worsted weight yarns are slightly heavier than DK weight yarns. They’re ideal to knit warm garments and sweaters, hats, and winter accessories. To work with these Group 4 Medium yarns, we recommend 4-4.5-mm knitting needles or a 5-6-mm crochet hook. One ball of 100 grams of (10 ply) Worsted weight yarn can consist of between 150-200 meters. These yarns usually have a WPI (Wraps per Inch) of 9-11.