Australian men are the world's longest lived, a new study has revealed, but the research shows that by 2030 they will have been knocked off the top spot for world life expectancy.

The study, published on Wednesday in The Lancet, shows that across the developed world life expectancies continue to climb, pushing above 90 for the first time.

Australian boys who were born in 2010 can expect to live to 80.10, the study says, longer than any other country. And those to be born in 2030 can expect to live to 84.00.

However, males born in South Korea in 2030 can expect to live to 84.07, or about 25 days longer than an Australian male born at the same time. Given the nature of the statistical modelling, this falls within the margin of error.