The Math Behind Fitting 175 Million People in Spain

From Monaco to Japan: The Arithmetic Trick of Density

A participant claims Japan has 3.5 times Spain's population density. This figure leads to the number driving the entire discussion: according to this calculation, 175 million inhabitants could fit within the country's 505,990 km², and even a conservative estimate suggests 100 million would suffice in fifteen years. The math adds up. The rest of the issue, however, does not.

Where Do the 175 Million Inhabitants Come From?

From the ratio between Japanese and Spanish density. If Japan hosts 3.5 times more people per square kilometer, replicating this ratio in Spain yields the cited figure. There's a more aggressive version of the same game, using Monaco's density: 36,000 inhabitants per km² multiplied by Argentina's 3 million km² would result in 108 billion people, thirteen and a half times the planet's population.

According to corrections made within the thread itself, the starting data is inflated. Milei, who made the calculation, admits "if I'm not mistaken," and the principality's actual density is around 19,000-20,000 inhabitants per km²; Argentina's area, excluding Antarctic claims, is 2.78 million km². Corrected, this yields about 53 billion, half the original figure. And Monaco imports 100% of its food, water, and energy. It's a shell game: the number impresses, and nobody notices the trick.

Water Decides More Than Square Kilometers

A territory isn't measured in square kilometers, but in irrigated hectares and cubic hectometers of reservoirs. And there, the sign flips: the scenario proposed by one participant points to resources to feed 20 million people at best, with agriculture dependent on importing fuel, fertilizers, pesticides, and certified seeds.

Adding 80 million mouths to that equation requires explaining where the wheat comes from. The most cynical answer circulating is electrical self-sufficiency based on solar panels and wind turbines, destroying every last cultivable hectare, with the most expensive energy bill in Europe. Another suggested path is allocating water and land to future data centers. India has 450 people per km², according to another message, but the parallel breaks down precisely when asking who pays for the imports.

Why Do France and Germany Handle Population Better Than Spain?

France and Germany have sustained much larger populations than Spain over comparable areas. The difference isn't in the total area but on the map: 90% of Spain's population lives in a few urban centers, while the interior empties out. This is the strongest argument for those who believe there's room: it's not a lack of land, but a lack of distribution.

In Málaga, the conversation is the opposite. Housing and service prices are rising, tourism dominates the city center, and some local residents are considering leaving. Some messages argue the problem isn't tourists but a municipal policy focused on them since 2000. The city doesn't have a kilometer problem: it has a money problem.

Immigration: The Variable That Slips Into the Calculation

Another current in the debate shifts the demographic discussion to immigration policy, with the proposal to condition naturalization on settling in depopulated areas. Some messages respond with explicit hostility towards newcomers. Others, however, call for labor – waiters in the Canary Islands, construction workers, bakers – and those jobs aren't in the depopulated areas.

Between these two extremes lies a blind spot. Healthcare, schools, transportation, and running water don't multiply by decree when a municipality suddenly doubles its population.

Can 175 million fit? In a spreadsheet, undoubtedly. The question no one has answered—neither with Monaco nor Japan as a reference—is how many can be sustained by the reservoir, the hospital, and August's payroll.