My grandson is 15 months. The size chart says he should wear a size 5. His cousin, the same age, wears a size 4 shoe. I bought these in both size 4 Med and size 5 Med. My daughter tells me the shoes were all too narrow. She loves the shoe, but she thinks that my grandson needs a 6.5 Med at age 15 months. I don't find any offerings in wide sizes.