India's demographics: the world's largest population, a below-replacement birth rate, and a census overdue

The structural picture: the numbers

India is the world’s most populous country. UN projections reported in mid-2023 put India’s mid-year population at about 1.4286 billion against China’s 1.4257 billion, the point at which India overtook China (UN DESA press release, https://www.un.org/development/desa/pd/sites/www.un.org.development.desa.pd/files/undesa_pd_2023_india-population_press-release.pdf). That milestone sits alongside a second, seemingly contradictory, fact: India’s fertility is now below replacement. The fifth National Family Health Survey (2019-21) recorded a total fertility rate of 2.0 children per woman, below the 2.1 level required to keep a population stable over the long run under current mortality (NFHS-5 national fact sheet, http://rchiips.org/nfhs/factsheet_NFHS-5.shtml).

The two facts are reconciled by demographic momentum. A population with a large share of young people continues to grow for decades after fertility falls below replacement, because there are many more women entering childbearing age than leaving it. India’s growth is therefore decelerating rather than stopping, and the policy conversation has shifted from limiting births — the frame of the National Population Policy 2000, which targeted replacement fertility by 2010 — to managing the age structure that below-replacement fertility produces: first a bulge of workers, later a growing share of the old.

The institutions and data systems

India measures its population through a distributed apparatus, not a single agency, and the seams between those instruments are where credibility is contested. The foundational count is the decennial census, conducted by the Office of the Registrar General and Census Commissioner of India under the Ministry of Home Affairs and made compulsory by the Census Act, 1948 (Census of India, https://censusindia.gov.in/census.website/en). Between censuses, the same office runs the Sample Registration System, the large sample survey that yields official birth, death, infant-mortality and fertility rates. The National Family Health Survey, run by the International Institute for Population Sciences for the Ministry of Health, supplies fertility and health indicators such as the TFR above. The working-age population, employment and — in the 2020-21 round — internal migration are measured by the National Sample Survey and the Periodic Labour Force Survey, run by the Ministry of Statistics.

The central strain in this system is that its keystone had gone missing for a decade and a half. The census due in 2021 was postponed in March 2020 because of the COVID-19 pandemic and was not restarted for years, leaving India without a completed headcount since 2011 — the longest such interval since the census began in 1881 (2027 census background, https://en.wikipedia.org/wiki/2027_census_of_India). In June 2025 the Office of the Registrar General notified the census by gazette (S.O. 2681(E)), fixing a reference date of 00:00 hours on 1 March 2027, and 1 October 2026 for the Union Territory of Ladakh and snow-bound areas of Jammu and Kashmir, Himachal Pradesh and Uttarakhand; caste is to be recorded for all groups for the first time since 1931, following the Cabinet Committee on Political Affairs’ decision of 30 April 2025 (2027 census background, https://en.wikipedia.org/wiki/2027_census_of_India). The Registrar General has described Census 2027 as India’s first digital census, with a web-based self-enumeration option in 16 languages and enumerator data collection by mobile app, conducted in two phases — house-listing and housing census, then population enumeration. As of mid-2026 the census is no longer merely notified but under way: the first phase of house-listing operations opened from April 2026 in an initial set of states and Union Territories, with more than three million enumerators and supervisors to be deployed (PIB, Registrar General’s Census-2027 press conference, https://www.pib.gov.in/PressReleasePage.aspx?lang=1&PRID=2246847&reg=3).

The demographic dividend and its window

The “demographic dividend” is the growth potential created when the share of the working-age population is large relative to dependants — children and the elderly. India’s dividend is real but time-limited. The government’s own analysis in the Economic Survey 2018-19 (Chapter 7, “India’s Demography at 2040”) projected that the share of the working-age population would keep rising for roughly two more decades and peak around 2041, when the working-age (20-59) group is expected to reach about 59% of the population, after which the ratio turns down as ageing accelerates (Economic Survey 2018-19, Chapter 7, https://www.indiabudget.gov.in/budget2019-20/economicsurvey/doc/vol1chapter/echap07_vol1.pdf). The median age is around 28, among the youngest of the large economies.

The dividend is contingent, not automatic, and this is where the debate is sharpest. It is realised only if the working-age population is educated, healthy and employed; otherwise a youthful population is a source of pressure rather than growth. The live argument, which connects this desk to labour policy, is whether the economy is generating enough formal jobs to absorb the workers the dividend supplies, and whether the window — often dated from the mid-2000s to around the 2040s — is being used or allowed to pass. Positions range from those who read the large youth cohort and falling dependency ratio as India’s central economic advantage, to those who argue that without faster formal-job creation and skilling the dividend risks becoming underused capacity. The dividend also varies sharply by state: southern and western states, having completed the fertility transition earlier, are ageing faster, while several northern states remain younger.

Ageing at the other end

The same fall in fertility that produced the dividend guarantees an ageing society behind it. UNFPA India and the International Institute for Population Sciences, in the India Ageing Report 2023, projected that the share of people aged 60 and over would roughly double from 10.5% in 2022 (about 149 million) to 20.8% by 2050 (about 347 million), and that the elderly would outnumber children under 15 by around 2046; the population aged 80 and above was projected to grow especially fast (UNFPA India, https://india.unfpa.org/en/news/india-ageing-elderly-make-20-population-2050-unfpa-report). Because the fertility transition ran at different speeds across states, ageing is uneven: some southern states are projected to have elderly shares well above the national average within a generation while others remain comparatively young.

Ageing links demographics to pensions, health financing and the elderly-welfare architecture housed under the Ministry of Social Justice and Empowerment and the Ministry of Health. The characterisation held across the range of positions is that India is a country that will grow old before it grows rich — reaching a high old-age share at a lower per-capita income than the ageing economies of East Asia and Europe did — and that the size of the old-age support burden depends on choices made during the dividend years.

Internal migration

India is a country in motion internally far more than across its borders. Census 2011 recorded about 45.6 crore internal migrants, roughly 37% of the population, the overwhelming majority of whom moved within their own state, chiefly women migrating on marriage; long-distance, inter-state labour migration was a smaller but economically decisive flow (PRS Legislative Research, https://prsindia.org/theprsblog/migration-in-india-and-the-impact-of-the-lockdown-on-migrants). The Economic Survey 2016-17, using railway-passenger data, estimated the annual inter-state migration flow at close to 9 million between 2011 and 2016 — well above the pace implied by the decennial census — and argued that internal migration for work was accelerating (Economic Survey 2016-17, migration chapter, https://www.indiabudget.gov.in/budget2017-2018/es2016-17/echap12.pdf).

Migration is where the data gap bites hardest in practice. Because the count is anchored to the last completed census (2011) and the recording of usual residence, the scale, direction and welfare needs of circular and seasonal migrants are poorly captured — a shortfall that became visible during the 2020 lockdown, when the number of migrant workers seeking to return home exceeded official expectations. This ties demographics to urban policy, since migration drives the growth of cities, and to the portability of welfare entitlements between the states migrants leave and those they enter.

The delimitation fault line

The most politically charged consequence of the census is delimitation — the redrawing and reallocation of parliamentary and assembly seats by population. The number of Lok Sabha seats per state has been frozen on the basis of the 1971 census since the 1970s, a freeze extended by constitutional amendment until the first census taken after 2026. Census 2027 is therefore the constitutional trigger that could reopen the allocation of seats. Because population growth has slowed much faster in the southern and western states than in several populous northern states, a strict population-based reallocation would shift relative seat-share toward the north. States that reduced their fertility fastest have raised the concern that they would be penalised in representation for succeeding at the population policy the centre set; other positions hold that representation-by-population is the constitutional norm and that mechanisms exist to manage the transition. As of 2026-07-28 the government has not published the formula or timetable for a post-2027 delimitation, and the range of positions described above is being argued rather than resolved. This connects demographics directly to the Election Commission and to the federal balance of power.

Settled vs contested

Settled: India is the world’s most populous country; the total fertility rate has fallen to 2.0, below replacement; the population is still growing on momentum; the census had not been completed since 2011 and Census 2027 is now under way, with population enumeration referenced to a 1 March 2027 reference date and a caste enumeration; and the elderly share is rising. These rest on official releases and UN and survey data.

Contested, and attributed as such: whether India is creating enough jobs to convert the demographic dividend into growth before the window narrows; how fast and how unevenly the country will age; the true scale of circular and seasonal migration, which the current data undercount; and how — or whether — parliamentary seats will be reallocated after the census, the single most consequential open question, on which the centre has published no formula. Where projections are cited (the 2041 dividend peak, the 2050 ageing share) they are model outputs from the bodies named, not certainties, and this brief characterises them as such.

Who owns this topic (and why we are here)

Public understanding of India’s demographics is split across the very institutions that produce the numbers and a layer of explainers that flatten them. The census office, MoSPI’s surveys, the IIPS/NFHS and UN agencies each publish authoritative slices, but no one of them holds the whole picture, and the gaps between them — a decade-and-a-half without a completed census, survey-based projections standing in for a count — are exactly where the story lives. Exam-preparation portals and encyclopedia entries summarise “the demographic dividend” and “the population policy” as static syllabus items, detached from the live institutional and political stakes. IndiaStand’s structural advantage is to hold the measurement system and the debate in one place: to track the census as an institution under the Registrar General and the Ministry of Home Affairs, tie the fertility and ageing numbers to the surveys and agencies that produced them, connect the dividend to labour and the census to delimitation, and attribute every figure to a primary or reference source — keeping the state of play current as the 2027 census phases run.

Maintained topic brief. Analysis by IndiaStand — it characterises the state of play and the range of positions actually held, attributes each claim, and makes no forecast and no recommendation.

questions: [“Is India the world’s most populous country and what is its population?”,“What is India’s total fertility rate and is it below replacement level?”,“When is India’s next census and why was it delayed?”,“What is India’s demographic dividend and when does the window close?”,“How fast is India’s population ageing?”,“How does the 2027 census affect delimitation of parliamentary seats?”]