Spirometry is the study of lung function, and there are a variety of measurements that can be used that are affected by age, gender, size and stature:
Tidal volume (TV) – the amount of inhaled/exhaled air
Minute ventilation (MV) – the amount of inhaled/exhaled air in 1 minute
Breathing rate (BR) – the number of breaths taken in 1 minute
At rest, breathing rate is optimally about 12-14 breathes per minute and the tidal volume about 0.5 litres per breath/6-7 litres per minute.