India is set to launch the world’s largest population census on Wednesday, deploying more than three million officials in a nationwide counting exercise expected to run for about a year.
The exercise, estimated to cost $1.24 billion, is described by the government as a “gigantic exercise of national importance” aimed at supporting inclusive governance and evidence-based policy planning in a country with an estimated population of about 1.4 billion.
Authorities say the census comes at a time when the country faces mounting pressure to meet growing demand for electricity, food, housing and urban infrastructure, particularly as major cities grapple with water shortages, pollution and expanding informal settlements.
The nationwide enumeration will be conducted in two phases. The first phase, starting Wednesday and continuing until September, will capture housing conditions and access to basic amenities through door-to-door visits and an online self-enumeration option supported by a satellite-enabled mobile application available in 16 languages.
The second phase will collect detailed demographic, social and economic data, including the politically sensitive issue of caste, a centuries-old social hierarchy that continues to influence access to education, jobs and public resources.
The inclusion of caste data presents a major policy challenge. A caste survey conducted in 2011 was never published due to reported inconsistencies, while the last comprehensive caste enumeration as part of a national census dates back to 1931 during British colonial rule.
Population counting across most parts of the country will take place in the weeks leading up to the reference date of March 1, 2027. However, enumeration in high-altitude Himalayan regions, including Jammu and Kashmir, will begin earlier, ahead of October 1, 2026, to avoid disruption from winter snowfall.
India has not conducted a census since 2011 after the 2021 round was postponed due to the COVID-19 pandemic. According to the last census, the population stood at 1.21 billion.
In 2023, the United Nations estimated that India had overtaken China to become the world’s most populous country, with more than 1.42 billion people.