My daughter wanted to wear her sleeveless version of this dress in the dead of winter, so I bought her a long sleeve version. She usually wears a 5T and I bought these in the size listed as 6-7 years old. She's almost 43 inches tall already, so I decided to make her a little bigger so she'll wear out more. The skirt hits the knees and the sleeves are slightly longer. The dress is very comfortable to wear and encloses the skirt perfectly. This dress gets a lot of positive feedback every time she wears it. I recommend that you base your size on your height, not your estimated age.