The sex ratio is a demographic indicator that measures the proportion of males to females in a population. In the context of India, it is defined as the number of females per 1000 males in the population.
The formula used to calculate it is:
\[ \text{Sex Ratio} = \left( \frac{\text{Total number of females}}{\text{Total number of males}} \right) \times 1000 \]
A sex ratio of more than 1000 indicates an excess of females over males, while a ratio below 1000 indicates a deficit of females. It is a crucial indicator of gender balance and social well-being in a society.