"normal" toilets are bowl height typically 14" to 14½". ADA bowls are usually 16" to 17" . Add roughly 1" to all of these for seat height.
There is no code I know of for "regular" bowls. A facility, like child care, may be required to have some childrens' 10" high, like the A/S Baby Devoro. Pubic facilities usually need to have "accessible" restrooms, meaning an ADA stall.