Wearing an XS in this black unitard / onesie from Universal Standard — I am size 14/16 for reference. I usually wear small in US but I sized down for a snug fit. The fabric is fantastic. I am not wearing a bra here. It has light support and full coverage. Straps are adjustable. I am 5’8 and have plenty of room in legs if I were taller LTKcurves LTKunder100