The largest organ in the human body is the skin. It covers the entire external surface of the body, with an area of about 20–22 square feet (2 square meters) in adults and a weight of approximately 3.6–4.5 kilograms (8–10 pounds)

. The skin serves as a protective barrier, regulates body temperature, enables sensation, synthesizes vitamin D, and plays a role in immunity and excretion

. If only internal organs are considered, the liver is the largest. The adult liver weighs between 1.2–1.5 kilograms (2.6–3.3 pounds) and performs over 500 vital functions, including detoxification, metabolism, and storage of nutrients

Organ| Type| Average Weight| Surface Area| Main Functions
---|---|---|---|---
Skin| External| 3.6–4.5 kg| 20–22 sq ft| Protection, sensation, temperature regulation, etc.
Liver| Internal| 1.2–1.5 kg| -| Metabolism, detoxification, storage, synthesis, etc.

In summary, the skin is the largest organ in the human body overall, while the liver is the largest internal organ