Your largest organ is the one you can see
Skin covers up to two square meters and accounts for roughly a seventh of your body weight.
The body’s largest and heaviest organ isn’t tucked inside the torso — it’s the skin. Spread flat, an adult’s skin covers about 1.5 to 2 square meters and weighs between roughly 3.5 and 10 kilograms, around one-seventh of total body weight.
It qualifies as an organ because it’s a coordinated system of tissues with defined jobs. It walls off germs and water loss, regulates temperature by sweating and adjusting blood flow, shields deeper tissue from ultraviolet light, makes vitamin D, and packs the sensors behind touch, pressure, heat, and pain.
Although skin is the largest organ, it isn’t the largest surface — the folded lining of the gut covers far more area.
The skin renews itself constantly, shedding dead outer cells and replacing them from below. That makes it not just the biggest organ but one of the most active — a living, self-repairing barrier between you and everything else.
Sources & references
2 referencesWell-established. Corroborated by 2 independent sources.
