These are cute but def run on the smallish side. I bought a small & they are pretty tight on my toddler who generally wears a size 6. They will certainly not last more than a month or so and he will outgrow them. So I would say that the small would only fit a size 5 comfortably. My son does love them & asks to wear them. I was just hoping that he would be able to wear them through fall/winter.