I'm 5'3" & 105# and bought the size 0. It mostly fits great, but the waist isn't tight and I'm afraid that, while for leisure that might be fine, for hiking and multiple days of wear without wash, the waist will stretch out and these won't stay up. I probably could wear a 00 but EB doesn't make that.Also, the zippered pockets aren't even close to being big enough for my S9+ phone. About 1/3 of my phone sticks out. Also, with the weight of the phone in a pocket, it pulls the pant down. Who wants to wear a belt with a backpack waist pack? not me.