I am very obese and I ordered a 4X but had to sew tucks in the elastic to get it to stay on because it was HUGE. I also decided to remove the inner polyester shell lining and one and a half tiers (one whole tier from the inner layer of mesh and half a tier from the outer layer) so that it could be worn more casually under dresses a bit shorter than this goes to on me. I've been wearing petticoats every day for years and this is an okay option, but I do wish I could figure out exactly what size to get that would stay up on my waist without riding all around during my day.