What is usually the volume of residual volume in milliliters?

The correct volume of residual volume, which is the amount of air that remains in the lungs after a person has exhaled as much as possible, typically averages around 1,200 milliliters. This volume is important because it prevents the lungs from collapsing and allows for continuous gas exchange even between breaths.

While 100 ml, 500 ml, and 1,600 ml may represent various other lung capacities or volumes under specific conditions, they do not accurately reflect the standard residual volume found in healthy adults. Therefore, understanding that the normal residual volume is approximately 1,200 ml helps clarify respiratory physiology and its implications for exercise and pulmonary function.