What is the normal respiratory rate for an adult?

• A. 8 to 12 breaths per minute
• B. 12 to 20 breaths per minute
• C. 20 to 24 breaths per minute
• D. 24 to 28 breaths per minute

Answer: (B)

The main idea tested is identifying the normal resting breathing rate for an adult. In healthy adults at rest, the typical respiratory rate is about 12 to 20 breaths per minute. This range reflects normal ventilatory drive and metabolic needs without distress. Rates below this, such as 8–12, are considered slower than normal (bradypnea) and can signal issues like sleep, certain medications, or neurological depression. Rates in the 20–24 range sit at the upper end of normal or may indicate mild tachypnea, sometimes due to anxiety or mild fever, but are not the standard resting rate. Rates of 24–28 or higher are usually tachypneic and suggest distress or underlying pathology. Counting for a full minute yields the most accurate assessment.