At 12:50am (AEDT) Australia's population hit 24 million according to the Australian Bureau of Statistics.
It estimates Australia's population changes at the rate of: one birth every one minute and 44 seconds; one death every 3 minutes and 24 seconds; and a net gain of one international migration every 2 minutes and 39 seconds.
This means the Australian population grows by one every minute and a half.
You can see the ABS' population clock here.
"Australia's population has added this recent million in record time, less than three years, so the population has added about 317,000 in the last year alone," social researcher Mark McCrindle said.
And it is migrants who have contributed to population growth the most since 2006.
While it's eased from its 2009 peak of 66 per cent, net overseas migration contributed to 53 per cent of total growth last year. The remaining 47 per cent is due to natural increases (births minus deaths).
"Migration is really the engine room of Australia's population growth and the workforce," Mr McCrindle said.
"We've got an ageing workforce here, we've got whole sectors here that are really underpinned by skilled migration - from agriculture to the construction sector."
The ABS says 72 per cent of Australia's population was born in Australia, that's down from 81.2 per cent in 1968, when Australia's population was 12 million.
Chris Richardson from Deloitte Access Economics says migration addresses the skills shortage.
"Anybody who puts up their hand to take a job earns an income, spends the income, and that creates the next job," he said.
The composition of Australia's migrant population has also changed. Mr McCrindle said more were coming from Asia.
"Three decades ago, the top countries of birth of Australians born overseas were European countries, plus New Zealand," he said.
"Today in the top five, along with New Zealand and England, you've got China, India and Vietnam."
At 1.4 per cent Australia's annual population growth rate is relatively high.
New Zealand, the US, the UK and China are at just above half a per cent, while Japan's population is decreasing.
The ABS projects Australia's population will reach 25 million in 2018 and will keep rising by a million persons every two to three years.
Mr McCrindle said he thought 40 million was just a few decades away.
"By 2050 based on the current growth trend, we'll have a population of 40 million, we'll be more densified and a lot more of us will be living in vertical communities, not just the horizontal ones, if we can build the infrastructure, we'll maintain the lifestyle that we know today," he said.
We'll have a definite population count when 10 million households across the country complete the 2016 Census on August 9.
