Average Adult Lung Capacity: Values and Influencing Factors

The average total lung capacity (TLC) for a healthy adult is approximately 6 liters (about 360 cubic inches).

Key Factors Affecting Lung Capacity

• Sex: Males typically have 20–25% larger TLC than females of similar height/age.
• Height: Taller individuals have larger thoracic cavities.
• Age: TLC peaks in early adulthood, then gradually declines due to reduced chest wall compliance and respiratory muscle strength.
• Fitness level: Athletes (especially swimmers, runners) often have higher vital capacities.
• Altitude: Chronic high-altitude residence can increase capacity.
• Disease: Obstructive (COPD, asthma) and restrictive (fibrosis, obesity) lung diseases reduce capacity.

Common Lung Volumes

• Tidal volume (normal breath): ~500 mL
• Inspiratory reserve volume: ~3,000 mL
• Expiratory reserve volume: ~1,200 mL
• Residual volume (cannot be exhaled): ~1,200 mL

Spirometry is the standard test to measure lung volumes and diagnose respiratory conditions.