What is the normal respiratory rate for adults?

• A. 18-30 breaths per minute
• B. 22-34 breaths per minute
• C. 12-20 breaths per minute
• D. 30-60 breaths per minute

Answer: (C)

The main idea is what a healthy adult’s resting breathing rate typically is. For a normal, resting adult, the breathing rate is about 12 to 20 breaths per minute. This range is used as the standard vital-sign benchmark because it reflects regular, quiet breathing without extra effort.

Counting breaths accurately means observing a full minute of rest, since short counts can under- or overestimate the rate. Several factors can push the rate higher temporarily—fever, anxiety, pain, exercise, certain medications, or lung or heart conditions—so the 12–20 range is the baseline for a resting state.

Among the options, the 12–20 range fits the standard resting rate. The other ranges describe breathing rates that are higher than normal at rest (such as 18–30 or 22–34, which would include many non-resting or stressed states) or are clearly outside the normal resting range (30–60). That’s why 12–20 is the best answer.