I ordered this in a large because at the time the medium was sold out. The large fits nice is not too big and it's not too tight. I honestly think it looks better in a large than they might've looked in a medium, depending on how you want to fit I would say size up if you want it to be a little looser in size down if you want it to be a little tighter and wear your normal size if you want it to fit regularly. Im 5'6 160 lbs, B Cup with a nice slim curvy body frame for reference