🫁 Clinical Reference Calculator
Lung Capacity Calculator
Estimate your Total Lung Capacity (TLC), Vital Capacity (FVC), and FEV1 in liters using clinical ERS reference equations based on your age, biological sex, and height.
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Clinical formulas require biological sex, height, and age for baseline anatomy.
Clinical Standard Reference:
Calculated with European Respiratory Society (ERS) / Quanjer GLI-2012 multi-ethnic reference equations for healthy adult lungs at sea level.
Predicted Lung Volumes
Max volume of air exhaled after full inhalation.
Key indicator for airway clearance and airflow speed.
Air remaining in lungs after all-out maximum exhale.
Clinicians consider an FEV1/FVC ratio above 70–75% a benchmark for healthy, unobstructed airways.
Test how well you use this volume:
Take the Breath Hold Test →Understanding Lung Capacity & Spirometry Numbers
Your lung capacity is not a single static number; it is divided into specific physiological compartments that reflect your thoracic anatomy, respiratory muscle strength, and alveolar elasticity.
Total Lung Capacity (TLC)
The maximum volume of gas your respiratory system can hold after taking the deepest possible breath. In healthy adult men, average TLC is approximately 5.5–6.5 liters; in adult women, 3.8–4.8 liters. Height is the single largest determinant of TLC because it correlates with the anatomical length and circumference of the ribcage.
Vital Capacity (VC / FVC)
The usable volume of air that you can voluntarily move in and out. During medical spirometry, this is measured as Forced Vital Capacity (FVC): you inhale to 100% capacity, then blast out as hard and fast as possible into a spirometer tube until your lungs are empty.
Does Bigger Lung Capacity Mean Longer Breath Holds?
Not necessarily. While having a larger Total Lung Capacity provides a slightly larger oxygen reservoir, breath-hold endurance is 80% determined by carbon dioxide tolerance and metabolic relaxation.
Untrained individuals often panic and release their breath within 25–30 seconds, even if they have 6.5 liters of lung volume, because rising arterial CO2 triggers a fierce urge to breathe. Conversely, trained freedivers and yogic practitioners with average lung sizes (4 liters) routinely hold their breath for 3 to 5 minutes by down-regulating heart rate and conditioning their chemoreceptors.
How Age Affects Lung Capacity
Lung capacity typically peaks between ages 20 and 25, followed by a gradual physiological decline of approximately 20–30 mL per year in non-smokers. This decline occurs because:
- Loss of Elastic Recoil: Alveolar walls lose elasticity, causing small airways to close earlier during exhalation.
- Chest Wall Calcification: Costal cartilage stiffens, requiring more muscular effort to expand the ribcage.
- Diaphragm Atrophy: Like any skeletal muscle, respiratory muscles lose force without regular aerobic stimulus.
Regular aerobic exercise (cycling, swimming, brisk uphill walking) and targeted breathwork like box breathing and diaphragmatic training preserve usable vital capacity and slow age-related decline.