Vital capacity is the sum of inspiratory reserve volume, tidal volume and expiratory reserve volume. It is about 4800 mL. Total lung capacity is the sum of vital capacity and residual volume, ie, vital capacity of our lungs is total lung capacity minus residual volume. Tidal volume is the amount of air, which normally passes into and out of the lungs during each cycle of quit breathing. It is about 800 mL in adult person. Inspiratory reserve volume is the extra volume of air that can be inhaled into lungs during deepest possible inspiration.