Minute volume is calculated as which formula?

• A. Tidal volume divided by respiratory rate
• B. Tidal volume times respiratory rate
• C. Tidal volume plus respiratory rate
• D. Respiratory rate minus tidal volume

Answer: (B)

Minute volume is the total amount of air moved in one minute. It comes from how much air is moved with each breath (tidal volume) and how many breaths occur each minute (respiratory rate). Multiply the two together to get the minute volume: tidal volume × respiratory rate. This yields a flow of air per minute, usually expressed in milliliters per minute or liters per minute. For example, a tidal volume of 500 mL with a rate of 12 breaths per minute gives 500 × 12 = 6000 mL/min (about 6 L/min). Using division, addition, or subtraction would not represent the total air moved per minute.