Infant mortality rate is the number of babies who die before completing 1 year of age, per 1,000 live births in a year. It is used to measure the health and development level of a country.

Class 9 definition

In simple Class 9 language, infant mortality rate (IMR) means:

  • Number of infant deaths under 1 year.
  • Calculated for every 1,000 live births.
  • Shows the quality of healthcare, nutrition, sanitation, and maternal care.

Formula

IMR=Number of deaths of infants under 1 yearNumber of live births in the same year×1000\text{IMR}=\frac{\text{Number of deaths of infants under 1 year}}{\text{Number of live births in the same year}}\times 1000IMR=Number of live births in the same yearNumber of deaths of infants under 1 year​×1000

This is the standard school-level formula used to explain infant mortality rate.

Example

If 20 babies die before age 1 out of 2,000 live births in a year, then:

IMR=202000×1000=10\text{IMR}=\frac{20}{2000}\times 1000=10IMR=200020​×1000=10

So, the infant mortality rate is 10 deaths per 1,000 live births.

Quick point

A lower infant mortality rate usually means better health services and living conditions.