Toilet seat heights vary, depending on the height requirements of the individuals who mostly use the fixture. The toilet seat may be designed with juveniles in mind, average-height adults or individuals with special needs.
The height that is standard on most toilets is between 14 and 15 inches. This height is the distance from the floor to the top of the seat on the toilet bowl.
The Americans with Disabilities Act provides design standards that adjust the toilet seat height to a more accessible level for individuals with special needs. Toilets are referred to as "water closets" in ADA Accessibility Guidelines. To be compliant with ADA guidelines, the height from the floor to the top of the toilet seat must be from 17 to 19 inches. For children, that height can be a minimum of 11 inches and a maximum of 17 inches.
With comfort in mind, toilet manufacturers have begun raising the seat heights to match more closely the standard height of chairs. With that in mind, toilets are available with seat heights ranging from 16 to 18 inches.