This is the third pair I've ordered. I,m about 5 feet tall and weigh about 105 lbs. I ordered size 18. I would probably swim in the women's size. I absolutely love these overalls and will order again. The only small negative thing about this particular pair is that the strength/durability of the fabric isn't as tough as the ones I ordered a few years ago. (double x denim instead of triple x denim)  This pair will wear out faster than the ones  from a few years ago. Aside from that I love them.