THE eldest of the "baby boomers" hit 65 this year, as Australia - on average - grows older.
New findings distilled from the 2011 census shows the average Australian is 37, 15 years older than it was when Australia became a united nation in 1901.
The figures come from Rafal Chomik, a senior research fellow at the Centre of Excellence in Population Ageing Research.
"At Federation, Australia was a youthful country with an average age of 22," he said.
Mr Chomik compared the difference in Australia's vintage to Daniel Radcliffe from Harry Potter and ageing American actor Mark Wahlberg.
"We're on our way from being a youthful magician to a retired welterweight champion."
The findings also suggested 2011 was the first year when over-60s outnumbered under-14s.
"These changing proportions demonstrate the demographic shift and the phenomenon we know as population ageing," he said.
The challenges of an ageing population will affect superannuation investment, health care spending and the cost of pensions.
Even if the average Australian is just over the hill in 2050, it could be worse.
In Japan, forecasts put the 2050 average age at 52.