The one year risk of death for an 80 year old man with a child was 7.4%, for example, compared with 8.3% for a childless man of the same age.
Fewer people are having children in Sweden as older people are spurning old-age institutions to receive care at home - often by their children.
The team found that having a girl had no extra benefit than having a boy, although previous studies have suggested that girls are more likely to help their ailing parents than their brothers.
Researchers from the Karolinska Institute in Sweden reviewed national registry data of more than 1.5 million people born between 1911 and 1925 and tracked them as they grew older.
"Children can provide support in navigating the healthcare system, how to take medication, providing emotional support", said Karin Modig, a co-author of the research in an interview with The Independent.
Everyone may have different viewpoints on when's the right age to have a child, but one thing for certain is that despite all the hardship, it is one of the most handsome experiences.
The study also found that fathers gained more in life expectancy than mothers.
The findings were similar for men and women who were 80 and up with children and those who did not.
At the age of 60, men who had children had nearly two years more on their remaining life expectancy than those without, at 20.2 and 18.4 years respectively.
The figures for women were 24.6 years and 23.1 years - a difference of 18 months. Men who were not married but had children were also living longer than those with a spouse.
"That the association increased with parents' age and was somewhat stronger for the non-married may suggest that social support is a possible explanation".
Men and women with at least one child had "lower death risks" than childless ones, the team concluded.
But while having children might boost the years left on your clock, Modig says it is far from the only factor influencing longevity.
The research showed that both married and non-married couples benefited from having children, though unmarried people - and particularly men- seemed to enjoy a stronger benefit.
That study, which looked at 1,600 adults with an average age of 71, found that almost 23 per cent of participants who were considered lonely died within six years of the study. "But it is still [about] a 1.5 percent difference, which is still substantial".
The associations were not affected by the sex of the child (ren), as has been suggested by previous research.
Additionally, individuals who were unmarried - particularly unmarried men - appeared to reap the greatest rewards from parenthood.
This could be because unmarried men relied more on their offspring in the absence of a partner.