The query "how tall is" is very broad and incomplete. It generally asks for a height measurement, but it lacks context — such as who or what's height is being asked about. To provide a useful answer, additional details are needed—for example, the specific person, animal, building, or object of interest. Heights vary widely depending on the subject. If the question means human height, average heights differ by country, gender, and other factors. For example, in the U.S., average male height is about 5'9" and female height about 5'4".
Please clarify the subject or object whose height is being inquired about so a precise answer can be given.