A normal resting adult respiratory rate falls within which of the following ranges?

• A. 8 to 15 breaths per minute.
• B. 22 to 24 breaths per minute.
• C. 12 to 20 breaths per minute.
• D. 10 to 18 breaths per minute.

Answer: (C)

At rest, a normal adult breathes about 12 to 20 times per minute. This range is the standard reference used because it represents effortless, resting breathing in a healthy adult. To assess it, count the breaths for a full minute, watching chest rise and fall rather than listening for each breath.

Rates above 20 suggest tachypnea and possible distress or physiologic stress, while rates below 12 point toward bradypnea, which can occur with sedation, central nervous system depression, or overdose. The 12–20 range is the best fit for a normal resting adult, while the other options fall outside this typical range.