Extremely small. Youth 4 is more like 2t. Unfortunately the tags popped off when I struggled to fit it over my kids head to see if I could have made it work for tomorrows waterpark trip. Unfortunately, I have to run to the mall and find a new one that is sized appriately. This is my 2 year old wearing it rather than my 5 year old)he wears a 2t and it just fits.