There is no standard height for a door viewer. The door viewer should be positioned so that the majority of people can use it, which will mean low enough to accommodate a majority of short people, because taller people can bend down to use it.
While this may be inconvenient for taller people, they can at least use it, whereas short people would need to use a step, which would be extremely inconvenient.
Other factors are the likely users. If there are likely to be wheelchair users or very short people it may be best to have two viewers.
Note that the viewer needs to be set for eye height, not head height.
Per the 2010 ADA guidelines, the height of the accessible door viewer should be at 42" to the center of the viewer from the floor.
48" Above Finished Floor
A standard interior door height is 2.032 metres. ( 2m 32mm.)
About 64 inches.
36 inches is the standard doorknob height.
The standard exterior door height is 80 inches. The standard exterior door width is 36 inches. The thickness of the door should be at least 3/4" thick.
The average height is about 180-185 cm... Boet.
A standard interior door height is 2.032 metres. ( 2m 32mm.)
standard height in u.s. is 6 foot 8 inches = 203.2 cm = 2.032 m
The standard garage door height is 7 feet (2.1 meters).
It depends on what kind you order standard is usually about 6foot8inches.
rResidential, USA is 6' 8".