You have about 5 litres of blood in your body (at least most people do) and the average heart pumps about 70 ml of blood out with each beat. Also, a healthy heart beats around 70 times a minute. So, if you multiply the amount of blood that the heart can pump by the number of beats in a minute, you actually get about 4.9 litres of blood, which is almost your whole body’s worth of blood. In just a minute, the hearts pumps the entire blood volume around your body.