How is Minute Volume calculated?

• A. Tidal Volume / Respiratory Rate
• B. Respiratory Rate x Tidal Volume
• C. Tidal Volume + Dead Space
• D. Inspiratory Reserve Volume x Respiratory Rate

Answer: (B)

Minute volume is the total amount of air moved in or out of the lungs each minute. It’s found by multiplying the amount of air moved with each breath (tidal volume) by how many breaths you take each minute (respiratory rate). So, minute volume = tidal volume × respiratory rate. For example, if tidal volume is 500 mL per breath and the rate is 12 breaths per minute, the minute volume is 6,000 mL per minute (about 6 L/min). This is the total air flow per minute, including air that fills dead space and doesn’t participate in gas exchange. If you want to know the portion that actually reaches the alveoli, you’d calculate alveolar ventilation as (tidal volume − dead space) × respiratory rate.