India’s population will touch almost 1.7 billion by 2050 but its child population (those below 15 years of age) is projected to come down by 20% over the next 32 years. The population of Indians above 65 will in the meantime increase almost three times. As a result, India will go from being characterised as a country with moderate child dependency at present to one with a high old-age dependency by mid-century, new population projections by the US-based Population Reference Bureau suggest.According to the projections, India’s population growth of about 22.5% will be lower than the 29.3% growth in global population, marking a radical departure from the past as Africa emerges as the continent pushing the growth of the global population. India’s aging is in line with the global trend. From over one out of every four people in 2018, the global population of children is projected to come down to about one in five or 21% by 2050.At the same time, the share of the 65+ population will rise from less than one in 10 in 2018 to about one in six. PRB, a private non-profit, collects and analyses demographic data from across the world. According to PRB projections, in India, children will form 19% of the population in 2050, down from 28% in 2018, while the proportion of those above 65 years will rise to 13% from 6%.The PRB report calculated the dependency ratio of various regions and countries. Dependency ratio is the number of people in a dependent age group (those under age 15 or ages 65 and older) divided by the number in the working-age group (ages 15 to 64), multiplied by 100. For instance, a child dependency ratio of 45 means there are 45 children for every 100 working-age individuals.Calculations based on the data given in the PRB’s World Population Datasheet 2018 show that in the 2018 to 2050 period, India is projected to go from a moderate child dependency ratio (defined as 29 to 45) of about 42 and low old age dependency ratio (15 or less) of around 9 to low child dependency ratio of 28 and high old age dependency ratio of 19.According to PRB, India is set to reach two major milestones in the next 10 years — it will surpass China to become the world’s most populous country and also reach replacement fertility as families have fewer children. Replacement fertility means that each couple has, on average, only enough children to “replace” itself in the population without increasing the size of the next generation.