I am a XL but I can wear L to even Medium sometimes. This is my own fault but I didn’t size up to the 1X so my breasts were spilling out the top. I love under boob but it wasn’t the good kind at all. If you’re a 38ddd like myself definitely size up to AT LEAST a 1X. It has size adjusting things but they are just for show as you cannot actually adjust the cup size. Just be wary and size up if you’re unsure your chichis will fit. 😭