I ordered the one size and was a bit worried I would need plus size but it fits perfectly. I was 200lbs two weeks ago before my c section, currently around 170 and 5ft 6. This gets nice and snug and all the pieces fit great. I have plenty of extra room so if unsure order the smaller size. I actually think I will want a smaller one in a few weeks and wish this came in s smaller size. My stomach is already flat, it never went back down this flat after my prior two c sections so I am beyond happy. Also helps with my post c section back pain. I was worried most of the reviews were from people getting the product at a discount but I paid full price so this is a honest review from a regular customer. Love it!