In a man weighing 200 pounds, the volume of anatomic dead space would be (approx.):

Although 150 mL is said to the volume of dead space in adults, it can not be exactly the same in every individual. Anatomic dead space volume would depend on the size of the respiratory system, which in turn would depend upon the body size. Hence, a rough estimate of the dead space volume can be determined as: anatomic dead space = 1 mL per pound of the body weight. This is known as Radford's formula