Aran weight yarn is heavier than worsted weight, and not as heavy as a bulky weight yarn. A perfect Aran weight yarn would be knit on a US 8-9 needle at 16 sts per 4 inches. It is important to note that many British patterns call for Aran yarn, which is what Americans refer to as worsted weight yarn. Aran weight yarn is perfect for a cozy oversized boyfriend sweater, and makes excellent rugged menswear. Use Aran weight yarn for quick, cozy pullovers and blankets, as well as outerwear cardigans and jackets.