This onesie is so cute! Perfect for my son to wear to the pumpkin patch! The color is so pretty and the material is nice and thick and soft. The product description says to size up, but I don’t suggest doing so. I order the 12-18 month size for my 13 month old (approx. 20 lbs., 31”) and it was pretty big on him. I ordered another onesie in the same size and this one was quite a bit bigger than the other one. It did shrink some in the wash but was still a little big even after washing and drying. I chose to keep it rather than exchanging for a smaller size so that he can wear it for a while! I would just stick with the child’s regular size tho, don’t size up!