The largest and heaviest human organ is the skin, with a total surface area of about 20 square feet (1.9 square meters) for an average person or 25 square feet (2.3 square meters) for a large person; it weighs 5.6 pounds (2.7 kilograms) on average representing four percent of the average weight of the human body. Although generally it is not thought of as an organ, anatomically it is an organ.