How much air is in a single breath?

Answer 1

The average adult at rest inhales and exhales something like 7 or 8 liters (about one-fourth of a cubic foot) of air per minute. That totals something like 11,000 liters of air (388 cubic feet) in a day.

Answer 2

The average human lung has a capacity of 6 liters (approximately).
This does not represent the amount you breathe however. Tidal volume is only 500ml or half of one liter. The tidal volume is what an average person inhales and exhales in a relaxed breath. Values are actually smaller for women. Average breaths per minute are between 9 and 20 times. Much higher for a novice Scuba diver on their first open water dive.

Answer 3

What you are asking is called Tidal Volume.

Tidal Volume is the amount of air exchange (entering or leaving) during an average breathe at rest.

That volume is approximately 500ML