Lung volumes

There are several different measures of lung volumes, some of which can be taken by Spirometry. They are:

1. Tidal Volume (TV)
   The volume of air inspired and expired over the course of a normal breath. This is around 500 ml
2. Inspiratory Reserve Volume (IRV)
   The volume of air that can be inspired over and above that of a normal (tidal volume) breath. This is around 3100 ml
3. Expiratory Reserve Volume (ERV)
   The Volume of air that can be expired over and above that of a normal breath. This is around 1200 ml
4. Residual Volume (RV)
   The volume of air that is left in the lungs after maximal expiration; that is after the expiratory reserve volume. It is around 1200 ml but cannot be measured by spirometry.
   

References

http://www.frca.co.uk/article.aspx?articleid=100023