Every item runs differently therefore there is no size chart that will work for certain for every person! Pay special attention to the product description where we note if items runs small, large, or are true to size. In general, 0,2, 4 = small, 4,6, 8 = medium, 8,10, 12 = large. Our model Peyton is typically a size 2 and wears smalls in most things, and occasionally mediums. It will be noted in our product description what size she is wearing. Our model Riley is typically a size 4 and wears mostly smalls and occasionally medium, this also will be noted in product descriptions. If you have any questions regarding sizing please contact us and thank you for shopping with us!