The number of children who die under the age of 5 years is usually expressed as a rate per 1000). Therefore, the under-5 mortality rate is defined as the number of children who die under the age of 5 years per 1000 live born infants. The under-5 mortality rate indicates the probability that a live born child will not survive to the age of 5 years. The under-5 mortality rate is one of the basic health indicators.