How much air is normally breathed in and out during a quiet breath?

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Medical illustration of the human chest showing the lungs, diaphragm, ribs, trachea, bronchus, and bronchioles, with one lung cut away to reveal internal structures. — human respiratory system The lungs serve as the gas-exchanging organ for the process of respiration.

During normal, quiet respiration, the amount of air that is inspired and expired in a single respiratory cycle is approximately 500 millilitres. This volume of air is known as the tidal volume.12