Old-age dependency ratio is the number of individuals aged 65 or older per 100 people of working age, defined as those aged between 20 to 64 years old.

The evolution of old-age to working-age ratios depends on mortality rates, fertility rates and migration. OECD countries have seen prolonged increases in life expectancy that most analysts project to continue, implying an increasing number of older people and most likely of pensioners too.

This indicator is measured as a percentage.