Despite the listing saying to purchase based on measurement I went ahead and ordered based on the shoe size my dgtr wears (size 4) and they are about 2 sizes too big.  That is my fault, knew it was a risk going into it.  I will not send them back because kiddos grow so fast I know she will be in them in the mean time.  I got them for a piano recital and was able to have her double sock and used mole skin around the sides and heel and they worked.  I was pleasantly surprised by the quality - they are great and even come with extra gems.  Really well packaged.  I wish more companies put that amount of effort into their product and could still make it affordable like this company.  I plan on ordering more colors (in the right size) for both my dgtrs.