Answer:The average adult has about 1.2 to 1.5 gallons 4.5 to 5.5 liters of blood circulating inside their body. If you had no blood, you'd weigh 8 to 10 percent less. Of course, you wouldn't be alive, either. So, for example, in a person weighing 120 lbs. (54 kilograms), blood takes up about 9.6 to 12 lbs. (4.4 to 5.4 kg).
Explanation:Dr. Daniel Landau, a hematologist and oncologist at the University of Florida Cancer Center Orlando Health.