What is the normal range for the adult respiratory rate per minute?

• A. 8-12
• B. 12-20
• C. 20-30
• D. 30-40

Answer: (B)

Normal resting respiratory rate for an adult is 12 to 20 breaths per minute. This range represents how often the lungs complete a ventilation cycle when a person is at rest and not exerting themselves. If the rate falls below 12, it’s bradypnea and may indicate CNS depression, sleep, or certain medications; if it rises above 20, it’s tachypnea and can be seen with fever, anxiety, pain, hypoxia, or respiratory illness. When measuring, count breaths for a full minute with the patient quiet and undisturbed to avoid misreading. Knowing this range helps flag potential respiratory problems early.