How many Indians are there, and where is the population heading?

How many Indians are there today, and how has the count changed since 1960?

India's population in 2024 is estimated at 145.1 crore people, according to the World Bank. In 1960, the country had only 43.6 crore. In a single generation, the number tripled.

This is not a censusCensusAn official count of every person in the country, usually done every 10 years. It provides the most accurate population figure.India's last census was in 2011; all current total population numbers are estimates, not counts. The 2024 census is underway. figure; the last full count was in 2011. All current numbers are estimates, built from surveys and population models. The line on the chart climbs steeply because death rates fell before birth rates did. Between 1960 and today, life expectancy nearly doubled, and famine was largely ended.

So for decades, the population swelled even as each woman started having fewer children. Today that momentum is still carrying the total upward, but the pace is slower. The next census, now under way, will give a fresher picture. For now, 145 crore is the best estimate of how many Indians are alive.

How does India's population compare to China and the world?

India's population of 145.1 crore now edges past China's 140.9 crore, making it the world's most populous country. The crossover happened around 2023. In 1990, China had 113.5 crore and India 86.5 crore; the gap has been narrowing for decades as China's fertility plunged earlier and its population has begun to shrink. The world population stands at 814.2 crore. Together, India and China account for about 286 crore people, more than a third of all humans.

The three lines on the chart, India, China, World, each show upward growth, but India's continues to climb while China's recently turned flat and may decline. This marks a historic shift: for the first time since the UN began such tracking, India is the most populous nation.

What share of the world's people are Indian?

India's share of world population was 14.4% in 1960. By 2024, it had risen to 17.8%. That means nearly one in every six people on the planet is Indian. The line on the chart moves upward steadily as India's growth rate outpaced the global average for much of the past six decades.

This share will likely continue to rise for a few more decades, as the world's population growth slows but India still adds people. But eventually, as India's fertility falls further and other regions grow, the share will stabilise and perhaps dip. For now, India's demographic weight is enormous: around 145 crore lives out of a global 814 crore. That is more than the entire population of every other country except China.

Where do Indians live, and how quickly are cities growing?

India is still mostly a rural country, but the urban share is rising slowly. In 1960, only 17.9% of Indians lived in urban areas. By 2024, that figure had crept up to 35.4%.

That means about two in every three Indians still live in villages. The pace of urbanisation is slower than many Asian peers. This matters for fertility because urban areas have much lower birth rates. The rural-urban divide in fertility is stark: rural women still average 2.1 children, while urban women average only 1.5. As more people move to towns and cities, the national fertility rate tends to fall. The chart shows a slow upward slope; urbanisation is happening, but not at the explosive pace some expect.

Is India's population still growing, and when will growth peak?

India's population is still growing, but the annual growth rate is falling. In the year 2000, the rate was 1.9%. The UN's median projectionProjectionA calculation of what the population would be in the future based on assumptions about fertility, mortality, and migration. It is not a prediction; different assumptions produce different projections.All future population figures are projections, and the range of outcomes shows we cannot be certain about the exact peak. shows it declining steadily: it will cross zero around 2061 and then turn negative, reaching -0.5% by 2100.

So the population will keep rising, but more slowly each year, until it peaks. The peak is not when the growth rate first falls, but when the rate hits zero. This delay is demographic momentumDemographic momentumThe tendency for a population to keep growing for decades even after fertility drops, because many young people are still entering childbearing age. Like a heavy train that keeps rolling after the engine is cut.India's growth today is mainly momentum from earlier high fertility, not current birth rates.: because about 68% of Indians are of working age (15-64) and many are young, births still outnumber deaths even though each woman has fewer children. The chart includes several UN scenarios; the high-fertility variant still has positive growth in 2100 (0.3%), while the low-fertility variant has a much deeper fall (-1.6%). The exact path depends on future fertility.

How many babies are born each year relative to the population?

The crude birth rateCrude birth rateThe number of live births in a year per 1,000 people in the total population. It is 'crude' because it doesn't account for whether the population is young or old.Used to show raw birth flow; India's SRS 2024 rate is 18.3., which counts live births per 1,000 people in the population, was 18.3 in 2024 according to India's Sample Registration System (SRS). This is down from 19.7 in 2019. The rural rate is higher: 20.2 per 1,000. In urban areas, it is 14.7.

So even though the total number of births is still huge because the population is huge, the rate at which Indians are having babies has been falling. The crude birth rate is a useful snapshot of how many births are happening relative to overall numbers, but it can be influenced by the age structure. A young population can have many births even if fertility per woman is low. The rural-urban gap is visible on the chart; it reflects both differences in fertility and differences in the proportion of women of childbearing age.

How many children does the average Indian woman have?

The total fertility rate (TFR) is the average number of children a woman would have over her lifetime at current birth rates. In 1960, India's TFR was 5.92, among the highest in the world. By 2024, it had fallen to 1.96, a drop of two-thirds.

This is not the number of children any specific woman has, but a composite snapshot. The chart shows a steady, almost linear decline since the 1960s, with a slight flattening recently. The fall is due to many factors: higher education, later marriage, more contraception, and economic change. The World Bank data reflects this long arc.

Today, at 1.96, India is just below the replacement levelReplacement levelAbout 2.1 children per woman, the level at which each generation exactly replaces itself in the long run, accounting for some children not surviving. Below 2.1, each generation is smaller than the last.India's TFR at 1.9 (SRS 2024) means it has fallen below replacement, signalling eventual population decline, though momentum delays it. of about 2.1 children per woman. That means the next generation, all else equal, would be smaller than the current one.

Is India's fertility below replacement level?

Yes. The replacement level is about 2.1 children per woman, the rate needed for each generation to exactly replace itself, accounting for some child mortality. India's SRS data for 2024 puts the national TFR at 1.9, below that threshold. The rural TFR is 2.1, exactly at replacement, while urban TFR is only 1.5.

So the national average is being pulled down by cities, even though most Indians still live in rural areas. The SRS tracks this closely. Since 2019, the national rate has fallen from 2.1 to 1.9. Once a country falls below replacement, it enters a new demographic phase: population will eventually stop growing and begin to shrink, though momentum can delay this for decades. The chart with three lines, national, rural, urban, makes the gap clear. Urban fertility is already far below replacement, while rural is just hovering at the line.

How does India's fertility compare globally?

India's fertility decline is part of a worldwide trend, but it now sits in the middle of the global pack. The World Bank chart plots many countries. India's line, at 1.96, is above all advanced economies (United States, Germany, United Kingdom, Japan, South Korea) and far above East Asia's ultra-low rates, South Korea is below 1.0. However, India is below some neighbours like Bangladesh and Indonesia. The world average is about 2.3.

India has joined the low-fertility world, but it is not exceptionally low. Its rate is still higher than most rich countries, and that difference matters because it means India's population will keep growing for longer than theirs. The chart also shows that fertility everywhere has been falling for decades. India's decline has been particularly steep and steady, converging with global norms.

How do Indian states compare to rich nations on fertility?

Stand India’s states beside the rich world, and the picture is startling. Tamil Nadu and West Bengal, with a total fertility rate of about 1.3, sit below the United Kingdom, Denmark, Iceland, Portugal, and Norway. They are level with Finland, and only Japan, at 1.2, is lower. Maharashtra, at 1.4, matches Norway. Kerala, Karnataka, Andhra Pradesh, and Telangana all register 1.5, putting them on par with Denmark, Iceland, and Portugal.

These are not outliers; several of India’s most populous states now have fertility rates that belong in the developed world, even though their income levels do not. For millions of Indian families, the two-child norm is now as entrenched as in Western Europe or Japan.

How did India reach low fertility with so few women in paid work?

In most countries, fertility falls as more women take up paid work. India breaks that pattern. Its total fertility rate is now just under 2.0, roughly the same as Vietnam's.

But while Vietnam got there with three-quarters of its women in the workforce, India's female labour-force participation hovers at barely a third. China and the United States, with fertility well below replacement, have over two-thirds of women working. Even Bangladesh, at a higher fertility of about 2.2, has nearly half of its women in jobs. India's journey to low fertility was driven not by formal employment for women, but by rising education, contraceptive access, and changing aspirations. This complicates the simple story that women's workforce entry is a necessary condition for fertility decline. ## Does fertility look different across India's states?

Yes, fertility is not uniform across India. The state-level map from NFHS-6 shows a clear north-south divide. In general, southern and western states have lower fertility, while northern and central states have higher.

This pattern has been known for decades, shaped by differences in female education, income, and social norms. The map uses colour coding: darker shades indicate higher TFR. Bihar, Uttar Pradesh, and other states in the Hindi belt stand out with rates above replacement. In contrast, Kerala, Tamil Nadu, and others are well below. The national average of 1.9 masks this internal diversity. The map is a snapshot, and internal migration means some states' fertility may be influenced by the movement of people, but the broad geographic pattern is persistent.

What will India's fertility map look like in a decade?

Official projections for 2031-35 paint a future where almost the entire Indian subcontinent converges to a fertility rate of about 1.5. That is well below the replacement level of 2.1. The map becomes nearly uniform, with only Bihar holding out at a projected 2.4. Madhya Pradesh is expected to be around 2.0, while Uttar Pradesh, Rajasthan, and Jharkhand come in at about 1.9.

These projections, from the National Commission on Population, are based on trends up to 2019 and must be read as scenarios, not certainties. In fact, several states are already falling faster than projected, suggesting the reality could be even lower. The post-transition era, where most women have two or fewer children, is approaching rapidly. ## Which states have the highest and lowest fertility?

The NFHS-6 data for 2023-24 ranks states. The highest TFR is in Bihar at 2.7 children per woman. The next four highest are Meghalaya (2.2), Jharkhand (2.2), Uttar Pradesh (2.2), and Rajasthan (2.1). All are above replacement.

At the other end, the lowest is Andaman and Nicobar Islands at 0.9, an extremely low rate. Next are Sikkim (1.0), Arunachal Pradesh (1.5), Delhi (1.6), and Punjab (1.6). These are far below replacement.

So the range is wide: from 0.9 to 2.7. A handful of states with large populations like Uttar Pradesh and Bihar pull the national average up; many others are already deeply below replacement. The table of top five and bottom five makes the contrast stark.

How fast is fertility falling across India's states?

The last decade has seen a breathtaking fall in fertility across India's major states. In about ten years, Bihar dropped from roughly 3.4 to 2.8, Uttar Pradesh from 3.3 to 2.6, Madhya Pradesh to 2.4, and Rajasthan to 2.3. Even the already low-fertility southern states kept declining: Tamil Nadu tightened from 1.7 to 1.3, and Kerala slid from 1.8 to 1.5. By 2023, only five states (Bihar, Uttar Pradesh, Madhya Pradesh, Rajasthan and Chhattisgarh) remained above the replacement line of 2.1. The speed matters as much as the levels.

Every state is moving in one direction, and the gaps are closing fast. The question is not if the high-fertility states will cross the line, but when. ## At what age do Indian women typically have children?

The age pattern of childbearing in India is compressed. The SRS age-specific fertility rates for 2024 show that births peak sharply in the 25-29 age group, at 134.7 births per 1,000 women. The 30-34 group follows at 78.3, and 20-24 at 105.5. Very few births occur to teenagers (10.9 per 1,000) or to women over 40 (11 per 1,000). The shape of the bars is like a bell, skewed right.

This means the average Indian woman now has most of her children in a relatively short window in her twenties and early thirties. The concentration reduces total fertility because each year of delay lowers lifetime births. The chart shows that by age 35-39, rates drop to 33; after 40, to 11. So childbearing is almost complete by age 35.

Are women having children later?

Yes, women in India are having children later than before. The UN median projection for mean age at childbearingMean age at childbearingThe average age at which women give birth, weighted by age-specific fertility rates. A rising mean age means women are having children later in life.India's mean age rose from 25.5 to 30.5 (UN projection), indicating delayed childbearing which lowers fertility. shows a rise from 25.5 years in 2000 to 30.5 years by 2100. The line on the chart moves gradually upward.

This reflects several changes: girls are staying in school longer, marrying later, and increasingly participating in the workforce. Even in the short term, delays in the age at first birth push down total fertility because the childbearing years are biologically limited. Later childbearing also often means fewer children overall, as couples stop earlier. The chart projects this trend out to 2100, assuming continued social change. If fertility remains constant, the mean age would stay lower, but UN projections anticipate that childbearing will shift later and later, as in all modernising societies.

Why are Indian families shrinking? The answer lies in the last birth.

The story of India's shrinking families is not about women starting childbearing much later. The age at first birth has crept up only slightly, from about 19.4 to 21.2 over three decades. What has changed dramatically is when women stop. The age at last birth has tumbled from roughly 32.8 to 27.6.

That is a compression of over five years in the childbearing window. As a result, women spend far less time in their reproductive lives actually having children. This earlier stop is driven by the widespread desire for small families, often two children, and the means to achieve it through contraception. The window is closing from the top, and that is what is driving India's fertility to new lows. ## How does India prevent pregnancy, and who bears that responsibility?

Contraception is the direct means by which fertility falls, and in India the method mix is heavily skewed toward female sterilisation. The NFHS-6 data shows that among married women aged 15-49, female sterilisation accounted for the largest share of modern method use, while male sterilisation was negligible. Female sterilisation is a permanent method, and it is often provided to women after they have had their desired number of children.

This pattern places the burden of contraception almost entirely on women. Unmet need for family planning, women who want to stop or delay childbearing but are not using contraception, remains significant. The chart compares different methods: any method, any modern method, female sterilisation, male sterilisation, and unmet need. The bars show female sterilisation dominating, a feature of India's family planning programme for decades. This reflects both accessibility and cultural expectations about who manages fertility.

Are families getting smaller?

Yes, the composition of births by birth order confirms that families are shrinking. In 2024, according to SRS, 66.4% of all live births were first children. Another 22.7% were second children. Only 7.3% were third children, and a mere 3.5% were fourth or higher order.

This means that nearly 90% of births are to mothers having their first or second child. The share of fourth-and-higher births has been steadily declining. Two decades ago, larger families were common; now they are rare. The chart of birth order percentages is a direct sign that below-replacement fertility has already reshaped the typical family. Most couples are stopping after one or two children, and the three or four child family is becoming unusual. This is consistent with the TFR of 1.9: the average woman stops after about two children.

How common is child marriage and teenage motherhood?

Despite overall fertility decline, child marriage and teenage motherhood still occur. The NFHS-6 data reports the percentage of women aged 20-24 who were married before age 18, a widely used measure of child marriage. Also, the share of women aged 15-19 who are already mothers or pregnant.

These figures are highest in poorer, more rural states. Over the last decade, both indicators have fallen, but they remain significant. Child marriage often leads to early childbearing, which can contribute to higher total fertility because these women spend more years at risk of pregnancy and may have less access to contraception. The chart presents these two figures side by side. While they do not dominate the national fertility picture, they indicate that at the margins, early marriage and early births persist, especially in certain regions.

Does fertility depend on a woman's education?

Fertility falls sharply as a woman's schooling increases. NFHS-5 data (2019-21) shows that women with no schooling had a TFR of 2.82 children on average. For women with less than 5 years of schooling, it dropped to 2.3. With 5-7 years, 2.21; 8-9 years, 2.12; 10-11 years, 1.88; and for those with 12 or more years, only 1.78. The gradient is steep and consistent.

Education delays marriage and first birth, increases knowledge and use of contraception, and often changes aspirations. It also gives women more agency within households. So schooling is one of the strongest predictors of lower fertility. The chart is a bar chart that makes the drop visible. Since more Indian girls are now completing secondary school, this trend alone will push national fertility further down over time.

Does fertility fall as households get wealthier?

Yes, fertility declines with household wealth. NFHS-5 data divides households into five wealth quintiles. Women in the lowest wealth quintile had a TFR of 2.63. In the second quintile, 2.12; middle, 1.89; fourth, 1.74; and the highest quintile, just 1.57.

That is more than a full child difference between the poorest and richest groups. Wealth influences fertility through several channels: richer households tend to invest more in each child's education, mothers may have more opportunities to work, and contraception is more accessible. But wealth and education overlap heavily; richer households also have more educated women.

So the two factors together explain much of the fertility decline. The bar chart shows a clear, monotonic downward slope from left to right. This gradient is a signature of modern demographic transitions everywhere.

Does fertility vary by religion?

Fertility levels differ by religious group, and this is often misunderstood. NFHS-5 data shows that Muslim women had a TFR of 2.36, Hindu women 1.94, Christian 1.88, Sikh 1.61, Buddhist/Neo-Buddhist 1.39, and Jain 1.6. So Muslim fertility is the highest among these groups, but still well below replacement in some groups and far below historical levels. The important context is that all religious groups have experienced a steep decline in fertility over the past few decades, and the gap between Muslims and others has narrowed. For instance, in NFHS-3 (2005-06), the Muslim TFR was 3.1 and Hindu was 2.6; the gap was 0.5.

By NFHS-5, the gap had shrunk to 0.4. Fertility is converging, not diverging. The differences today are primarily linked to socioeconomic factors like education and poverty, rather than religion per se. The chart simply presents the numbers; what matters is the trend toward convergence.

How many girls are born for every boy in India?

The sex ratio at birthSex ratio at birthThe number of girls born per 1,000 boys. A natural ratio is around 950-970 girls per 1,000 boys; lower numbers indicate missing girls, often due to sex-selective practices.India's ratio of 918 (SRS 2022-24) signals persistent son preference, though it has improved. in India is skewed toward boys. The SRS reports a ratio of 918 females per 1,000 males for the period 2022-24, a three-year moving average. This is below the natural ratio of around 950-970 girls per 1,000 boys, indicating that some girls are 'missing' due to son preference and sex-selective practices. The ratio has improved from 907 in 2018-20, but the distortion remains. The rural ratio is lower (914) than the urban ratio (928), meaning the imbalance is more severe in villages.

The chart shows three lines: all-India, rural, urban. Over the past few years, the lines have moved upward slightly, but they are still far from natural levels. This matters because a skewed sex ratio can create social tensions and reflects deep-rooted gender preferences. The data does not tell us why directly, but the pattern is clear.

What does India's population look like by age and sex?

India's age-sex structure in 2030, projected by the UN, is a classic pyramid with a wide base and a narrow top, but it is evolving. The pyramid shows both sexes separately. The largest age group is 0-4 years with about 11.1 crore children (both sexes). The pyramid is broad up to age 30, reflecting past high fertility. Above age 30, the numbers start declining, and after 60, they shrink sharply.

Females outnumber males in older ages because women live longer. The shape indicates a young population overall, but the base is already narrower than it was in the past. In 2000, the under-5 group was larger relative to the total. The pyramid is a snapshot, but it is drawn from projections, so it shows what the population might look like in 2030, not a current census. It reveals the demographic momentum: the large cohorts of young adults will keep having children, but each new cohort is smaller than the one before, so the base will continue to narrow.

How is the mix of children, working-age adults, and elderly changing?

The shares of three broad age groups have shifted dramatically. In 1960, children (0-14) made up 40.6% of the population; by 2024, that share fell to 24.6%. Meanwhile, the working-age population (15-64) rose from 56.1% to 68.2%, giving India a potential demographic dividend. The elderly share (65+) rose from 3.3% to 7.1%. The chart with three lines crossing over time shows these transitions.

The children's share has been declining steadily; the working-age share is now near its peak and may soon start to fall as fertility continues to drop and the large cohorts age. The elderly share will only increase. This shifting composition means that while India still has a large workforce, the dependency burden, especially of the old, will rise in the coming decades. The chart makes visible the window of opportunity before ageing accelerates.

How old is the typical Indian, and where is that heading?

The median ageMedian ageThe age that divides the population into two equal halves: half are younger, half are older. It is a measure of how old a population is overall.India's median age is rising from 21 to nearly 48 by 2100 (UN median), showing rapid ageing., the age that splits the population in half, was just 21.2 years in 2000. The UN's median projection shows it rising to 47.8 years by 2100. That is a doubling.

Today, India is a young country: half its people are under about 28. But within a few decades, the median will cross 30, then 40. The line on the chart moves upward, more steeply after 2040. Other scenarios vary: the high-fertility scenario keeps the median lower (39.4 by 2100), while low-fertility pushes it to 57.7. The median age is a quick summary of population ageing.

Like the old-age dependency ratioOld-age dependency ratioThe number of people aged 65 and older per 100 people of working age (15-64). It gives a rough sense of the economic burden of supporting the elderly.As India ages, this ratio will rise sharply, putting pressure on families and social systems., it is locked in by fertility. Once fertility is below replacement, the median age will inevitably rise. The chart shows that even in the most optimistic scenario for fertility, India will age substantially.

How many older Indians will each working-age person support?

The old-age dependency ratio, the number of people aged 65 and older per 100 people of working age (15-64), was 7.35 in 2000 (UN median, 65+/15-64). By 2030, it is projected to be 12.4, and it will continue to rise to much higher levels later in the century. The chart shows the trajectory. In 2000, for every 100 working-age Indians, there were about 7 elderly. By mid-century, that could be 15 or 20, and by 2100, far higher.

This ratio matters because it gives a rough indicator of economic support: more elderly relative to workers can mean greater strain on pensions, healthcare, and family resources. There are different measures; some narrower ones (like 65+/20-64) yield slightly different numbers. The chart uses the most common measure. The upward curve is relentless, driven by falling fertility and rising life expectancy.

How long are Indians living today?

Life expectancy at birthLife expectancy at birthThe average number of years a newborn would live if current death rates stayed the same throughout their life. It summarizes mortality conditions.Rising life expectancy (from 46 to 72) means more Indians reaching old age, accelerating ageing. in India has almost doubled since 1960, from 45.6 years to 72.2 years in 2024, according to World Bank data. This is a remarkable improvement driven by better healthcare, sanitation, nutrition, and living standards. The line on the chart shows a steady upward trajectory. Each additional year of life expectancy adds more people to the older age categories. Combined with falling fertility, longer lives accelerate population ageing.

Women tend to live longer than men, so the elderly population is disproportionately female. The chart is a simple line, but behind it are millions of stories of reduced infant mortality and controlled infectious diseases. Life expectancy at birth is a summary measure; it does not guarantee any individual will live that long, but it reflects the overall health environment of the country.

What share of Indians are now elderly, and what does that mean?

The share of the population aged 65 and over was 3.3% in 1960; by 2024, it reached 7.1%. That is still relatively low compared to rich countries, but the growth is accelerating. The chart shows the share rising, and in projections it will climb steeply after 2030.

This is the "ageing" signal. India is still in the early stages of population ageing, but the direction is clear. As fertility remains below replacement, fewer children are born and the proportion of elderly grows. The rapidity of this change is what makes the "old before rich" concern acute: India is ageing at a much lower income level than Western Europe or East Asia. The elderly share alone does not fully capture the pressure; the old-age dependency ratio is more directly about support. But the share is the most intuitive indicator: in 1960, only 1 in 30 Indians was elderly; today it is about 1 in 14, and it will become 1 in 6 by mid-century.

How wealthy is India as it grows older?

India's GDP per capitaGDP per capitaTotal economic output (goods and services) of a country divided by its population, in current US dollars. It's an average, so it doesn't reflect how much a typical person earns.India is ageing with a GDP per capita around $2,700, far lower than rich countries when they aged, raising the 'old before rich' concern., a measure of average economic output per person, was only $85 in 1960. By 2024, it had risen to $2,695. That is a thirty-fold increase, but in current US dollars, it is still low. The chart shows a rising line, but the level is far below the thresholds at which rich countries faced ageing. When Japan and Western European nations aged, their incomes were $20,000 to $40,000 or more per person.

India is greying at a fraction of that affluence. This means there is less fiscal capacity for universal pensions, social security, and elder care. The burden will fall heavily on families, especially women. GDP per capita is an average; inequality means many Indians earn far less. The chart is a line on a linear scale, but the message is about a profound misalignment: the population is ageing faster than the economy is prospering.

When will India's population peak and start declining?

According to the UN's median projection, India's population will peak around 2061 at about 1.70 billion people. It will then plateau for a few years before beginning a slow decline. By 2100, it is projected to be about 1.51 billion, close to where it is today.

So the total increase from now until the peak is about 250 million, roughly the population of Brazil. The line on the chart rises, crests, and then gently slopes downward. This peak is not a sudden stop; it is a gradual levelling off and turning. The exact year and magnitude depend on future fertility.

But the direction is robust: the population will eventually stop growing because fertility is already below replacement and life expectancies are increasing only slowly. This projection is central to planning for everything from schools to pensions. The chart extends from 2000 to 2100, so you can see the long rise and the expected decline.

How high could India's population go? Different UN scenarios to 2100.

The UN produces many projection scenarios to show how sensitive the future is to fertility. The median scenario gives the peak at 1.70 billion. But the high-fertility scenario, where fertility stays just slightly above replacement for longer, results in a population of 2.20 billion by 2100 and still growing. The low-fertility scenario, where fertility drops faster and stays lower, yields a much smaller population of 991 million, with a steep decline after mid-century. The chart shows a fan of lines spreading out after 2050.

The differences are huge. The low-fertility line is almost half the high-fertility line by 2100. This spread shows that the future is not predetermined. Policies on family planning, female education, and child health will shape which path India follows. But all scenarios agree that growth will slow and eventually reverse, because even the high scenario assumes fertility will eventually decline.

How does the IHME model compare to the UN projection?

The Institute for Health Metrics and Evaluation (IHME) published a different model in 2020 that projects an earlier and lower peak for India's population. IHME's reference scenario sees fertility falling faster than the UN assumes, leading to a peak around 2048 at about 1.61 billion, and then a sharp decline to about 1.09 billion by 2100. The UN's median peak is around 2061 at 1.70 billion.

So the two most-cited models disagree by about a decade in timing and about 600 million people by 2100. The chart puts both lines on the same axes. The IHME projection is more pessimistic about future fertility, it assumes that as female education and contraception increase, fertility will drop quickly, following the path of many East Asian countries. The UN is more conservative, assuming a slower decline. Both are informed extrapolations, not facts. The truth likely lies somewhere in between, but the divergence is a reminder that population projections are uncertain.