The average adult human body contains about 4.5 to 5.7 liters of blood, which is roughly 7-8% of the person's body weight. This volume varies depending on factors such as age, sex, body size, and physiological conditions. For example, adult males typically have around 5.5 liters, while adult females have slightly less, about 4.3 to 4.5 liters. Pregnant women have 30 to 50% more blood volume to support fetal development. Children and infants have proportionally more blood relative to their body weight, with infants having about 75 to 100 milliliters per kilogram of body weight
. In summary:
- Adults: ~4.5 to 5.7 liters (7-8% of body weight)
- Pregnant women: 30-50% more than non-pregnant adults
- Children: 8-9% of body weight
- Infants: 9-10% of body weight (about 75-100 ml/kg)
This blood volume supports vital functions such as oxygen transport, nutrient delivery, and temperature regulation
