I have 4 sweatshirts now. Love them all but this one is especially soft. I’m 5’4”, 120# so I decided to try an XS instead of my usual small but ended up exchanging it for a s. The XS fit but snugger than I’d like. I think if you’re really tiny the XS will be fine. I’m older so I think we are broader in the back and waist though I typically wear a 4/6. It’s a little big but I can tuck it as shown on the model or wear it loose. Intend to wear it for cool evenings in the desert as well as on our typical cold October days in PNW.