Australia’s median age: the age profile and the generations

Australia’s median age was 38.4 years at 30 June 2025. Half of the estimated resident population of 27,611,026 people were older than that age and half were younger. The median age for females was 39.3 years, 1.8 years higher than the 37.5-year median for males¹.

The median is a midpoint, not the mean. The mean age is calculated by adding the ages of all residents and dividing by the number of residents. Australia’s mean age was 40.0 years, 1.6 years above the median¹. The mean is higher because ages extend to 100 and over while the population is concentrated at younger ages. In 2025, 59.2 per cent of people were aged under 45.

The 30 June 2025 estimates are preliminary and will be revised². The next quarterly update, covering the March quarter 2026, is due on 17 September 2026¹.

Tasmania had the oldest population of any state or territory in 2025, with a median age of 42.53 years, while the Northern Territory had the youngest, at 33.76 years, a gap of 8.77 years¹.

South Australia had the second oldest, at 40.60. New South Wales, at 38.59, and Queensland, at 38.56, were just above the national median of 38.43, while Victoria, at 38.01, Western Australia, at 37.89, and the Australian Capital Territory, at 35.73, were below it.

Tasmania’s median age also increased more than that of any other state or territory between 2006 and 2025. It rose by 3.63 years, from 38.90 to 42.53 years, compared with an increase of 1.76 years nationally¹. The Northern Territory’s median increased by 2.78 years, from 30.98 to 33.76, and Queensland’s median increased by 2.50 years, from 36.06 to 38.56. The medians for New South Wales and South Australia both increased by 1.79 years. Victoria had the smallest increase, of 1.23 years, from 36.78 to 38.01.

Tasmania also had the highest share of people aged 65 and over of any state or territory while the Northern Territory had the lowest. In Tasmania, 22.4 per cent of residents were aged 65 and over in 2025, compared with 17.5 per cent nationally¹. In the Northern Territory, the share was 9.6 per cent. South Australia, at 20.5 per cent, was the only other state or territory above 20 per cent. The Northern Territory had the largest share of children aged 0 to 14, at 20.1 per cent, while Tasmania had the smallest, at 15.9 per cent.

People aged 30 to 34 formed the largest five-year age group in Australia in 2025, with 2,064,838 people, or 7.5 per cent of the population¹. The 25 to 29 group, at 2,025,212 people, and the 35 to 39 group, at 2,018,659, were the next largest. Every five-year group from 25 to 44 had more than 1.9 million people. The 0 to 4 group, at 1,517,283 people, was smaller than every five-year group between 15 and 64.

Across broader groups, 4,803,760 people, or 17.4 per cent, were aged 0 to 14¹. A further 17,967,879, or 65.1 per cent, were aged 15 to 64, and 4,839,387, or 17.5 per cent, were aged 65 and over. For the first time since the estimates began in 1971, people aged 65 and over outnumbered children aged 0 to 14, by 35,627. In 2024, there were 4,794,964 children and 4,697,558 people aged 65 and over.

In 1971, children aged 0 to 14 made up 28.7 per cent of the population and people aged 65 and over made up 8.3 per cent. The share aged 65 and over more than doubled over the 54 years to 2025, while the share aged 85 and over increased from 0.5 per cent to 2.2 per cent. The share aged 15 to 64 changed less, from 63.0 per cent in 1971 to 65.1 per cent in 2025.

The number of people aged 65 and over for every 100 people aged 15 to 64 increased from 13.2 in 1971 to 26.9 in 2025¹. Over the same period, the number of children aged 0 to 14 for every 100 people aged 15 to 64 fell from 45.5 to 26.7.

How the ABS projects these shares to 2071 is covered in the population projections article.

Australia’s median age was 22.5 years at 30 June 1901 compared with 38.4 years at 30 June 2021⁵. The median rose from 22.5 years in 1901 to 30.8 years in 1946, then fell or remained unchanged through to 27.5 years in 1970, a decline of 3.3 years over 24 years. It first reached 30 years in 1942 and did not return to that level until 1983.

After 1970, the median decreased in only two years. The historical data show decreases from 37.3 years in 2012 to 37.2 in 2013, and from 37.3 in 2015 to 37.2 in 2016. More recent ABS data show no change between 2012 and 2013, at 37.25 years, and a fall of 0.02 years between 2015 and 2016. The difference is due to rounding, as the historical figures are shown to one decimal place and the more recent figures to two. Over the 120 years from 1901 to 2021, the median increased by 15.9 years.

The historical figures and the December 2025 figures overlap from 1971 to 2021 and agree to within 0.05 years in every year. Before 1971, the historical figures are based on the number of people present in Australia rather than the estimated resident population. Before 1921, median ages are calculated from five-year age groups, so the earlier figures are not directly comparable with those from 1971 onwards.

The births and deaths behind natural increase over the same period are covered in the births and deaths in Australia article.