What is the normal breathing rate?

Normal breathing rates per minute vary according to age. According to About.com, newborns and infants take 30 to 60 breaths per minute, toddlers take 24 to 40 breaths, preschoolers take 22 to 34 breaths, school-age children take 18 to 30 breaths and adults take 12 to 18 breaths per minute.

About.com states that respiratory rates are measured while a person is at rest. Self-administering a breathing rate test is not recommended; medical staff often check breathing rates undetected to ensure an accurate score. A higher-than-normal breathing rate is often caused by lung and heart conditions. A breathing rate lower than normal may be caused by brain conditions, alcohol or narcotic usage or sleep apnea.