Thai fisherman's Pants are worn by many people who aren't Thai fishermen. They're unisex, the material they are made with is lightweight and extremely comfortable, and the adjustable waist makes it perfect for women who are pregnant or for anyone who needs a wide range of movement without being confined by a waistband (such as when exercising or backpacking.
Fisherman's Pants are so comfortable to wear. I wear these most of the year round. Both designs come in a free size ie one size fits all.
One size fits all, but figuring out how to tie these pants around your waist can be tricky without instructions.