I went to a store and had my son measured- he came in at size 5.5 US and the staff suggested this meant buy a 6. This shoe in 6M fit my babys chubby fat feet great and the flexible thin sole is perfect for a new walker. Hes so proud of his shoes- what a cutie!

I would not recommend this shoe for children that run- they are too thin to absorb impact and really are ideal for newer walkers.