I bought this as kind of a filler because the price was about 2 or 3 $. My daughter is 21 months and normally wears upto 2T. However I bought it in 3T just so she can wear later on. However, when it arrived i noticed it looked REALLY small. So, i put it on her to try and its just the right size for her to wear now for a short time. Meaning, it runs very small on size. I would order 1 or even 2 sizes bigger if you don't want it to be so snug. The material is kind of stretchy as well, may be polyester. The only reason i kept it is so she can use it as a play out in the dirt type of shirt or for coloring etc.