My daughter is 4 and 8 months and it’s baggy in the crotch and butt. 3-4 would have been too small I’m afraid. She loves it though so I’ll hang on to it.Nice suit. Love the adjustable shoulder straps!My daughter loves sharks so this was a big hit. It's cute and fits well. But she's worn it twice now and I've noticed that the sharks look more peach flesh tone rather than gray. I'm pretty sure they have bleached out in the pool. It's not hideous, just a little odd. Oh well, you can still tell what they are and the other colors are just as bright.My granddaughter loves cats and when I saw this I ordered right away!!! She loves it and it fits perfect!!I ordered a 5-6 and got a Medium and it was a bit baggy which I don't necessarily mind because at least she can grow into it. Also it has adjustable straps so really the only baggy bit is the butt and crotch area.I ordered a size up for my granddaughter and do glad I did. Fits her perfectly and she loves it. She's 9, so she's able to put it on very easily herself, no issues.Bought this for my 4 yo daughter and it fits great.Was too small but a cute swimsuit with pastel colors