I bought the small size for my 2 year old knowing it would probably run a bit big. The packaging says 3-5 years. I am sending it back because the proportions are wrong. The pants are probably 4T-5T if placed in front of my 4 year old. The top fit my 2 year old well, the sleeves were too long as expected. However, it looks more like a short jacket than the first photo with a person in it. Didn't notice before, but if you look at the 2nd photo with a mannequin, the length of the jacket is shorter. The front of the jacket, below the buttons where there is an inverted V-neckline, touches my 2 year old above the belly button. It is strange. If the proportions were better I would let him for his size.