The lung capacity of adults is usually 2500-3500ml for women and 3500-4000ml for men. lung capacity refers to the maximum strength of inhalation, and then the maximum strength of exhalation, the exhaled air volume is the lung capacity, including tidal volume, compensatory exhalation volume, compensatory inhalation volume 3 parts. Spirometry is different for everyone, and it is commonly used in life to measure spirometry to determine the quality of the human body, but everyone’s age is different, gender, height, thoracic elasticity, the strength of the respiratory muscles will have an impact on spirometry, normal male spirometry, if often exercise to reach more than 5000ml, the elderly, children’s spirometry will be reduced.