Spain’s population will hit 53.8 million by 2041 on immigration alone, INE projects, as one-person homes overtake couples

National growth depends entirely on foreign arrivals

The National Statistics Institute (INE) published its 2026–2041 population projections on Wednesday, showing Spain adding 4,251,150 residents over 15 years to reach 53,841,249. The entire increase is owed to international migration. Births will remain below deaths every year through 2040, yielding a consistently negative natural balance.

The population increase would be due exclusively to international migration.

Net migration is expected to start at 626,000 in 2026 (similar to the 626,268 recorded in 2024) and then taper off, but remain positive. Cumulatively, migration will add 6.3 million people through 2040 and 15.5 million by 2075. The share of residents born in Spain is projected to fall from 79.8% to 59.6% over the next 50 years.

Regional divergence: the northwest shrinks, the east booms

Not every community benefits equally. Four regions will lose population: Extremadura (−4.5%, a drop of 47,868), Asturias (−1.6%, 16,528 fewer), Castilla y León (−1.0%, 23,046 fewer) and Galicia (−0.5%). Ceuta also loses 2%. Within Castilla y León, the losses are concentrated in León (nearly 21,000 fewer residents), Zamora, Salamanca and Palencia, while Segovia and Burgos gain population. In contrast, the strongest growth is forecast for the Mediterranean arc: Valencia +16.4%, the Balearics +16.2%, Madrid +14.4%, Catalonia +12.2% and Murcia +12.2%. Together these five regions will account for half the country’s population.

For some large regions, the demographic motor is almost entirely external. In Castilla y León, the native-born population is projected to shrink by 9.7%, while the foreign-born community surges by 58.7% to 494,798, softening but not reversing the overall decline.

Households reshaped: living alone becomes the norm

A parallel household forecast points to a historic shift. By 2041, single-person households will reach 6.7 million, or 30.6% of all households, edging out two-person households (30.5%). The share of people living alone will rise from 11.3% to 12.5% of the total population. Castilla y León will have the highest share of solo households (39.2% in 2041), followed by Asturias (37.7%) and the Basque Country (36.7%); the Balearics remain lowest at 25.9%.

Average household size continues its decades-long descent, falling from 2.49 in 2026 to 2.43 in 2041. The proportion of larger households shrinks: those with three members slip from 19.8% to 18.5%, while those with four or more dip from 22.7% to 20.4%. The proportion of elderly will also climb sharply; the over-65 share peaks at 30.9% in 2076, and the number of centenarians grows thirteenfold to 259,810.

Beyond 2041: peak and slow retreat

The INE also offers a longer horizon. Spain’s population would crest at 54.6 million around 2051 before edging down to 53 million by 2076. Even a modest uptick in births later in the century, when larger foreign-born cohorts reach childbearing age, is not expected to reverse the trend.

This enduring reliance on migration, combined with the hollowing-out of rural and north‑western provinces, will define the country’s demographic contour for decades to come.