How many people have lived in the world?

About 107 billion – roughly 16 times the current population of the planet. The calculation was made by researchers at the Population Reference Bureau website (www.prb.org), which gathers data on demography. The numbers are obviously very approximate, starting with the first year of human life on Earth: for lack of a better option, they assume that in the year 50000 BC there were two inhabitants on the planet – the first man and the first woman. From then on, the account is divided into periods and is based on the average birth rate of each period. For example: from 50000 BC we jumped to 8000 BC, when man discovered agriculture and the birth rate exploded. During this period, the population went from 2 to 5 million inhabitants, following an average birth rate of 80 births per thousand inhabitants. In the following periods, the birth rate fell until reaching the current 23 births per thousand. Adding up all the periods, prb.org reached, in 2002, the result of 106.4 billion people. We add to this number the most recent data from the UN, which reports that, in 2007, we reached the mark of 6.7 billion inhabitants, that is, 485 million more people than the 6.215 billion that existed in 2002. Thus we arrive at a total of 106.941 billion inhabitants.