At the end of 2018, the city-state of Berlin had 3.75 million registered inhabitants in an area of . The city's population density was 4,206 inhabitants per km2. Berlin is the most populous city proper in the European Union. In 2019, the urban area of Berlin had about 4.5 million inhabitants.  the functional urban area was home to about 5.2 million people. The entire Berlin-Brandenburg capital region has a population of more than 6 million in an area of .