Every stat tells a story.

2021 Census shows Millennials overtaking Boomers

Media Release

The 2021 Census of Population and Housing has delivered a snapshot of the different generations that make up Australia.

The latest data reveals that, within a very small margin, numbers of Millennials (25-39 years old) have caught up to Baby Boomers (55-74 years old) as the largest generational group in Australia. In the 1966 Census, nearly two in every five people (38.5 per cent) were Baby Boomers.

Baby Boomers and Millennials each have over 5.4 million people, with only 5,662 more Baby Boomers than Millennials counted on 10 August 2021. Over the last ten years, the Millennials have increased from 20.4 per cent of the population in 2011 to 21.5 per cent in 2021. In the same time, Baby Boomers have decreased from 25.4 per cent in 2011 to 21.5 per cent in 2021.

Dr David Gruen AO, Australian Statistician, said “The data collected by the Census assists governments and community organisations to understand the needs of each generation. We see that an increasing number of Baby Boomers are needing assistance with core activities – with 7.4 per cent reporting a need for assistance, compared to 2.8 per cent across the younger generations. This information will help frame policy that delivers positive outcomes for our communities.”

Census data shows the important role Baby Boomers are providing in caring for other peoples’ children, often their grandchildren. Around one in eight (12.8 per cent) Baby Boomers reported caring for other peoples’ children, and of these two thirds are female (67.5 per cent). They are also the generation most likely to volunteer and provide unpaid assistance to others.

Millennials are of working age and are upskilling, representing 40 per cent of people attending vocational education, including TAFE, and 48 per cent of people currently serving in the regular service of the Australian Defence Force.

Millennials and Baby Boomers report quite different religious affiliations, with nearly 60 per cent (56.8 per cent) of Baby Boomers reporting a Christian religious affiliation compared to 30 per cent of Millennials (30.6 per cent). More than 45 per cent (46.5 per cent) of Millennials reported that they had no religion compared to 30 per cent of Baby Boomers (30.7 per cent).

Generation Z (10-24 years old) represent 18 per cent of Australia and 30 per cent of the Aboriginal and Torres Strait Islander population.

For further information about 2021 Census data, tune into the 2021 Census data release launch on 28 June at 10am AEST at http://www.abs.gov.au/census/events or explore the data at www.abs.gov.au/census/find-census-data.  

How the generations have been defined for this purpose:


Generation Alpha

Generation Z

Millennials  (Gen Y)

Generation X

Baby boomers



0-9 years

10–24 years

25-39 years

40-54 years

55-74 years

75 and over

Year of Birth

2011 - 2021

1996 - 2010

1981 - 1995

1966 - 1980

1946 - 1965

1945 or earlier

Media notes

  • For media requests and interviews, contact the ABS Media Team on media@abs.gov.au or 1300 175 070.
  • Further information on 2021 Census is available in the Census media backgrounders.
  • When reporting ABS data you must attribute the Australian Bureau of Statistics (or the ABS) as the source.
  • Subscribe to our media release notification service to get notified of ABS media releases or publications upon their release.
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