Such a good set, I had to go back for another! I have this set in blue in a medium top and small bottom, fits perfectly! However with the yellow, I wanted it a little looser since the color is lighter. I got a medium in the yellow bottoms. I love the fit of both, the yellow is just a little more baggy. These sweats are stretchy so I don’t think you can go wrong either way depending on the type of fit you want! LTKgrwm LTKootd LTKmomlife