science & techanalysisOur World in Data
Average life expectancy worldwide has more than doubled since 1900
Around 1900 the average newborn could expect to live roughly 30 years, and today the global average is above 70. Most of the gain came from falling child deaths, as infants and children stopped dying from infections, diarrhoea and childhood diseases. Clean water, sanitation, vaccines, antibiotics and better nutrition all played major roles. Adults now also live longer, because heart disease, cancer and infections are treated far more effectively.
Life expectancy is the average age a newborn could expect to reach if current death rates stayed the same. When child mortality falls, the average rises sharply because so many years are added for each child who survives. Public health measures reduced early deaths first, and medical advances later extended adult lives.
The rise shows that most of our longevity is a modern achievement rather than a natural condition. It also explains why the question of how long people can live is now about ageing itself rather than basic survival.
Life expectancy in rich countries rose from around 40 in the 1800s to over 75 by the late twentieth century, following a similar sequence of sanitation, vaccination and antibiotics. The same path is now being followed across much of the world.
