Body
How much blood is in the human body?
4.5–5.5 litres
How much blood is in the human body?
An average adult human has approximately 4.5–5.5 litres of blood — about 7–8% of total body weight. Women tend to have slightly less than men due to lower average body mass. Blood makes up about 8% of body weight and circulates through the entire body in roughly 60 seconds at rest.
Source: Standard physiology; Guyton & Hall Medical Physiology