How many oxygen liters you respire by minute?

An average adult male breathes approximately 12 times per minute with each breath bringing about 500 ml of air into the lungs. This represents about 6000 ml (or about 6 liters) of air per minute. Since about 21% of the air that we breathe is oxygen, we can say that we breathe approximately 6 * 0.21 = 1.26 liters of oxygen every minute.