I bought these for my very active 2 year old son. He loves the penguin design and the fact that they light up, but they are a little big for him so he has a hard time running and playing in them. He normally wears a size 6 or 7 and I ordered these in a 7. He definitely could have used a 6. The front part of the sandal where the toes / ball of the foot go is not adjustable so if your child has narrow feet they will most likely be too large. Otherwise they are great.