I bought the largest size. But it runs tight. My granddaughter will not let me return it. She loves it. But it won’t fit long.My daughter loves itGot this for my daughter on her 7th birthday. Bought the biggest size available which is a USA 10. But, it fits more like a 6. It’s shorter than I’d expect. Usually a 10 on her goes past her knees but this one is barely past her butt. It’s like a long T-shirt. Other than that it’s been great.