What's the Difference Between Aran and Worsted Weight?

While they're both considered medium weight yarns, worsted yarn is finer than aran weight yarn. Worsted yarn is often knit on 4.5mm needles with a gauge of 4.5-5 stitches per inch. Aran weight yarn is thicker and often loftier than worsted yarn.

Can I use worsted weight instead of Aran?

Sometimes you'll even see patterns use Aran and worsted interchangeably, noting that you can use a worsted/Aran weight yarn. ... But the two are not exactly interchangeable, especially in the U.S. Aran actually weighs slightly more than worsted yarn.

Is Aran weight yarn heavier than worsted?

Heavy worsted/Aran weight yarn is just slightly heavier than worsted weight yarns. Good for the same range of projects as worsted weight and will result in a slightly heavier fabric with more structure, heavy worsted/Aran weight yarns are typically knit on US 7-9 needles.