For context , I’m 5’7 n a half / 175lb / slim /athletic build . So I purchased this jacket along with 3 other ones & by the time I tried this one on , I pretty much learned my sizes when it comes to cropped jackets on FN website lol but I ordered a S & my actual size is M/L depending on what it is. THIS baby , fit like a TRUE S & I wish I would of just went off the comments since eveerybody purchased their true sizes but In the end , it wasn’t a loss cuz it fits , just a TAAAAD bit tight in the arms. I’m hoping once I start working out again (I’m coming for some FN athletic merch) it’ll be more fitting where I can move comfortably & not have it hugging my arms (it ain’t TIGHT but it’s still a noticeable snug type fit) … now that I think about it .. I did have a sweatshirt on lol so hopefully with just a spaghetti strap or some , it’ll be better but DEFINITELY purchase your normal size or you can size up or 2 for an oversize fit. I don’t think sizing up 1 will be a DRAMATIC difference as far as oversize . May just be more of a slightly increased wiggle room in arms & lil bit in the body area when zipped compared to sizing up 2 times for a REAL oversized look. Hope this helps my girls out there looking to buy 🥰