Which countries have already passed peak population, and when will the rest do so?

A peak population occurs when a country’s total number of inhabitants reaches its highest point and then begins to decline permanently.

This decline is not temporary, like during a war or famine, but a long-term trend driven by consistently low birth rates.

For example, in 2026, 64 countries and territories had already passed this peak, according to United Nations estimates.

Most of these countries are in Europe and East Asia, where birth rates have dropped sharply over decades.

Some countries, like Japan and Italy, reached their peak population more than ten years ago, while others, such as Thailand and Uruguay, have only recently passed it.

The decline is structural, meaning it is expected to continue unless birth rates rise significantly or immigration increases.