Standard bathroom vanity cabinets will be 21 inches deep. The standard height for a bathroom vanity is 32 inches tall. Some homeowners, especially those who happen to be taller than average, choose to install non-standard sized vanities in their bathrooms. The vanities can easily be built the same height as a kitchen countertop, which is 34.5 inches. Some builders are customizing vanities to suit the homeowner’s needs, though, and it is not uncommon to see vanities with heights up to 36 inches in some new custom built homes. Split level counters are sometimes seen, as well, in master bathrooms. Lower-than-standard heights may be seen in children’s bathrooms.