According to the University of Rochester Health Encyclopedia, the usual breathing rate in an adult is 12 to 16 breaths per minute at rest. However, fever, illness or other medical conditions often affect the respiratory rate.
According to WebMD, the respiratory rate of infants and children is different from that of an adult. Infants aged newborn to 6 months breathe on average 30 to 60 times per minute, while the usual rate per minute for infants aged 6 months to 1 year is 24 to 30 breaths. The normal respiratory rate for children 1 to 5 years of age is 20 to 30 times per minute, and for children 6 to 12 years it is 12 to 20, slightly faster than an adult. As with adults, various things may affect a child's rate of breathing. For example, fever, exertion, abdominal distension, heart problems, anemia and a number of other issues may cause rapid breathing (tachypnea), according to the Family Practice Notebook.