What does 50% higher mean?
UN global population estimates put life expectancy at birth at 73.3 years in 2024. Multiplying that figure by 1.5 gives 109.95 years, or about 110. This is arithmetic for a thought experiment, not a UN projection. It does not mean everyone would live to 110 or that the maximum human lifespan would become 110.
The WHO definition of life expectancy at birth describes an average based on the age- and sex-specific death rates prevailing in a particular population and year. It is a period measure, not a prediction of one person's lifespan. A 50% increase in that measure differs from adding 50% to the remaining life expectancy of someone who is already 60.
Population size and age structure
The outcome depends on which age groups gain survival, as well as fertility and migration. As context, rather than a forecast for this thought experiment, the OECD Pensions at a Glance 2025 report projects that across OECD countries the number of people aged 65 and over per 100 people aged 20 to 64 will rise from 33 in 2025 to 52 in 2050. Its projection has several drivers, including fertility, life expectancy and migration.
If survival improved mainly at older ages while other conditions stayed fixed, the balance between older and working-age people could change. The 50% premise alone does not specify those age-specific changes and cannot determine a population total or dependency ratio. The UN's separate projection of global life expectancy at birth reaching 77.4 years by 2054 is not a simulation of the 110-year illustration.
More life is not automatically more healthy life
The WHO healthy life expectancy indicator is distinct from total life expectancy: it estimates years in the equivalent of full health after accounting for health loss. A longer life could bring more healthy years, more time with health limitations, or a mixture. The hypothetical gives no information to determine which pattern would occur.
Work and pensions
The OECD pensions report describes policy mechanisms that adjust retirement ages or benefit levels to life expectancy. The implications for a particular pension system would depend on its rules and on employment. A longer life would not automatically mean a longer career.
As present-day context the OECD Employment Outlook 2025 reports an average employment rate of 55.9% for people aged 60 to 64 across OECD countries in 2024, with large differences between countries. This is a description of employment under existing conditions, not an estimate of what a 50% longevity increase would cause.
Care capacity
The OECD Health at a Glance 2025 report expects demand for long-term-care workers to rise as populations age and informal care changes. It also reports an existing projection of annual long-term-care spending growth of 2.6% through 2050 across OECD countries. These are OECD baseline findings, not a cost estimate for the 50% scenario.
How many additional years are healthy would matter to care needs. The precise effect would depend on health, the support people need, informal care and service arrangements. No particular care cost, retirement age, or individual outcome follows from the 50% premise alone.
The conditional answer
About 110 years is the arithmetic result of multiplying the 2024 global period estimate by 1.5. Demographic, health, work and pension effects require an explicit model of mortality by age and assumptions about fertility, migration, health and policy. The evidence above provides context for those questions; it does not predict the consequences of the much larger hypothetical increase.
