Very small in my experience. Bought size 6 for my 5 year old who wears size 6 from different brands. Did not fit. Was too small and tag said '5-6' so I sent it back and ordered the next size up, tag 'size 7' says '6-7' still too small had to go for "Size 8" come back again. Luckily the return was very easy and the dress itself is very cute and made of good material, it just runs small.