How much human organs weigh depends on which body organ you are discussing. The largest organ on the human body is the skin, and it weighs in at least six pounds. The pancreas, however, is a tiny organ and weighs only a few ounces. The average weight for the human brain is about three pounds. All other organs generally weigh between three and seven pounds. Overall, the human organs make up about 12% of the total body weight of a human being.