The volume of Blood in a Human body to be approximately ____ of body weight?

1. 2%
2. 5%
3. 7%
4. 50%
5. 70%

Scientists estimate the volume of blood in a human to be approximately 7 percent of body weight. An average adult with a weight of 150 to 180 pounds will contain approximately 1.2 to 1.5 gallons (4.7 to 5.5 liters) of blood.