I am 5'11", purchased a x-large for the length.  Nice flowy fit and the bottom hit just above my ankles like the model.  I think it was big on the body and i prob could have had a large for that but since this item is meant to fit loosly no once can tell. Perfect on a breezy beach day.  I would normally wear med or large clothes depending on the style and brand to give you an idea of my body type.