The proportions used in figure drawing are:
An average person, is generally 7-and-a-half heads tall (including the head).
An ideal figure, used when aiming for an impression of nobility or grace, is drawn at 8 heads tall.
A heroic figure, used in the heroic for the depiction of gods and superheroes, is eight-and-a-half heads tall. Most of the additional length comes from a bigger chest and longer legs.