Normal cardiac index in an adult is

Cardiac index: - Cardiac output per square meter of body surface area. i.e. Cardiac index = Cardiac output/Body surface area Experiments have shown that the cardiac output increases approximately in propoion to the surface area of body. The average human being who weighs 70 kilograms has a body surface area of about 1.7square meters, which means that the normal average cardiac index for adults is about 3 L / min/ M2 of body surface area.