Australia is heading toward a very different demographic future. Population projections have long pointed to continued growth, with migration playing a major role alongside births and deaths.
An Australian Bureau of Statistics projection published in 2018 estimated that the country’s population could reach about 40 million around 2066 under its medium series. The same projection put the possible 2066 population range between 37.4 million and 49.2 million, depending on assumptions about fertility, life expectancy and overseas migration.
These figures should not be treated as a guaranteed future population. The ABS explains that population projections are illustrations of what could happen if the underlying assumptions were to continue. Changes in migration, birth rates and mortality can produce very different results.
Migration is a major part of the story
One of the biggest factors behind Australia’s long-term population growth is net overseas migration. This is the difference between the number of people arriving to live in Australia and those leaving to live overseas.
The ABS uses different migration assumptions when building population projections. In its 2017-based projections, the medium series assumed net overseas migration of 225,000 people a year, while the low and high series used 175,000 and 275,000 respectively from the later years of the projection period.
Recent data also show how significant international migration is to Australia’s population change. In the year ending March 2026, about 557,500 people immigrated to Australia while about 265,400 people emigrated, according to the ABS. That difference contributes directly to population growth.
Births are also adding to the population
Migration is not the only source of growth. Australia’s population also increases when births outnumber deaths.
In the year ending March 2026, Australia recorded around 292,500 births and 191,900 deaths. That produced a positive natural increase of roughly 100,600 people before taking migration into account.
However, the longer-term picture is more complicated.
Australia’s fertility rate has been relatively low, and the ABS projects that the gap between births and deaths will gradually become smaller in some scenarios as the population ages. In its 2022-based projections, the ABS says natural increase could decline substantially over the projection period.
This means future population growth is increasingly sensitive to migration assumptions.
Australia’s population is also getting older
Population growth does not simply mean more young people.
The ABS’s latest national projections show that Australia’s median age was 38.5 years in 2022. Depending on the assumptions used, it could rise to between 43.8 and 47.6 years by 2071.
The share of people aged 65 and over is also expected to increase.
This creates a major demographic change alongside population growth. Australia could have more residents overall while also having a larger proportion of older people.
That will influence demand for healthcare, aged care, housing, transport and other public services.
Why the number can change so much
Long-term population projections depend on several moving parts.
A small difference in annual migration can become a very large difference when repeated over several decades. The same is true for fertility and life expectancy.
The ABS therefore publishes multiple scenarios rather than treating one number as certain. Its latest 2022-based projections put Australia’s population in 2071 between 34.3 million and 45.9 million across the selected low, medium and high series.
Under the medium series, the population reaches about 39.2 million by 2071. The high series reaches about 45.9 million, while the low series reaches about 34.3 million.
The difference demonstrates just how strongly assumptions can affect the eventual result.
The 40-million figure needs some context
The headline figure of almost 40 million by 2066 comes from the ABS’s earlier 2017-based projection series.
Under that projection, Australia’s population was estimated at 24.6 million in 2017. The medium scenario placed the population at 40 million around the middle of the following decades, while the full range of scenarios produced substantially different outcomes by 2066.
The ABS has since released newer projections based on a 2022 population starting point. Those newer figures should be used when discussing Australia’s more recent long-term demographic outlook.
So the 40-million figure is useful for understanding how earlier projections viewed Australia’s growth, but it should not be presented as a precise prediction of Australia’s population in 2066.
Cities will feel much of the change
Population growth is also closely connected to where people choose to live.
Large cities attract migrants, workers, students and families, while internal migration can shift population between states and territories.
This means national population growth does not automatically translate into equal growth everywhere. Some regions can grow quickly while others experience slower growth or population decline.
The ABS therefore produces projections not only for Australia as a whole but also for individual states, territories and capital-city areas.
What a larger population could mean
A larger population can bring more workers, consumers, businesses and demand for services. It can also increase the need for housing, transport infrastructure, schools, hospitals, energy and other facilities.
The effects will depend heavily on where population growth occurs and how quickly infrastructure and services expand.
An older population adds another layer to the challenge. Governments and communities will need to plan for both population growth and changes in the age structure.
The long-term picture is still uncertain
Australia’s population is clearly expected to grow under the main ABS projection scenarios, but the exact size of the country several decades from now remains uncertain.
Migration levels can change. Birth rates can move higher or lower. Life expectancy can develop differently from current assumptions. Economic conditions and government policies can also influence migration and population patterns.
That is why the ABS stresses that its projections are not forecasts or predictions. They show what could happen under particular demographic assumptions.
The possibility of Australia reaching around 40 million people is therefore best understood as part of a much larger demographic story. Migration is a major driver, natural population increase still contributes, and longer life expectancy is changing the age structure.
Over the coming decades, the important question will not simply be how many people Australia has, but how the country adapts its housing, infrastructure, workforce and public services to a population that is both larger and older.