A person's average total lung capacity is about 5.8 liters and is typically only reached during strenuous physical activity. A person's normal inspiration, or intake of air, is about 0.5 liters, according to hypertextbook.
There are many additional factors that impact a person's normal lung capacity, including height, weight, age, gender and overall health, reports hypertextbook. Taller people generally have a larger lung capacity than shorter people, and men generally have about 20 to 25 percent higher capacity than women. People who smoke tobacco also are found to have a much smaller lung capacity than nonsmokers, and athletes are often found to have a larger capacity than average.