Vital Index is the ratio of two vital statistics, that is, the births and deaths. It is defined as the ratio of the total number of live births to the total number of deaths in a given population over a specified time period (such as a year). Generally, it is more than one though for a specific region or period it may even be less than 1. It throws light on the likely growth of the population.

It can be calculated using the formula,

\text{Vital Index }=\frac{\text{Total live births in the population during the period}}{\text{Total deaths in the population in the same period}}.The index is a short-term measure of the registration of vital statistics indicating the degree of error in the registration of either births or deaths or more.

**Example:**

If there are 1500 births in a given population over a year and 1000 deaths over the same period then the vital index can be calculated as,

\text{Vital Index }=\frac{1500}{1000} = 1.5.