Between 2015 and 2080, according to the central scenario:Portugal will lose population, from the present 10.3 to 7.5 million residents, and falling below the threshold of 10 million in 2031.
The population aged under 15 will decline from 1.5 million to 0.9 million; even considering increases in the total fertility rate, a decrease in the number of births still occurs, due to the reduction of women at childbearing age, given the low fertility levels of the past years.
The number of elderly will increase from 2.1 to 2.8 million.
Given the decrease of the young population, along with the increase in the elderly population, the aging ratio more than doubles: from 147 to 317 elderly people for every 100 young people.
The aging ratio will only tend to stabilize in the 2060s, when the generations born in a context of fertility levels below the replacement level enter the 65 and over age group.
These trends will in general occur in all NUTS 2 regions (Norte, Centro, Área Metropolitana de Lisboa, Alentejo, Algarve, and autonomous regions of Madeira and the Açores).
The working age population will decline from 6.7 to 3.8 million people.
The potential sustainability ratio (number of persons aged 15-64 per 100 persons aged 65 and over) may decline sharply, due to the decrease of the working age population and the increase of the elderly population. This ratio will drop from 315 in 2015 to 137 in 2080.