What size shoe does a 2 year old boy wear?

My son just turned 4 and wears a size 11, though I think his feet are a bit bigger than average. My son is a five years old and he has what I think are HUGE feet. A size 1 at his last measurement. I'm sure girls and boys are at approx. the same growth rate at this point (pre-puberty). My nephew is also five and his feet are a size 12. Hope this helps! 11 or 12. I have two children. I have done daycare for years and this seems to ring true