Total lung capacity (TLC): the entire gas volume of the maximally spontaneously inflated pulmonary parenchyma and airways in the thorax.
Among healthy adults, the average lung capacity is about 6 liters. Age, gender, body composition, and ethnicity are factors affecting the different ranges of lung capacity among individuals.
TLC rapid increases from birth to adolescence and plateaus at around 25 years old. Males tend to have a greater TLC than females, while individuals with tall stature tend to have greater TLC than those with short stature, and individuals with a high waist-to-hip ratio generally have a lower TLC.
Formula:
Total lung capacity = IRV + TV + ERV + RV
Where,IRV is Inspiratory reserve volume
TV is Tidal volume
ERV is Expiratory reserve volume
RV is Residual volume