Estimates of historical world population

In many early attempts, such as in Ancient Egypt and the Persian Empire, the focus was on counting merely a subset of the population for purposes of taxation or military service.

[8] The more dramatic phrasing of "the living outnumber the dead" also dates to the 1970s, a time of population explosion and growing fears of human overpopulation in the wake of decolonization and before the adoption of China's one-child policy.

Arthur C. Clarke in 2001: A Space Odyssey (1968) has the claim that "Behind every man now alive stand 30 ghosts, for that is the ratio by which the dead outnumber the living", which was roughly accurate at the time of writing.

[10][11] The answer depends on the definition of "people", i.e., whether only Homo sapiens are to be counted, or all of the genus Homo; due to the small population sizes in the Lower Paleolithic, however, the order of magnitude of the estimate is not affected by the choice of cut-off date substantially more than by the uncertainty of estimates throughout the Neolithic to Iron Age.

An estimate on the "total number of people who have ever lived" as of 1995 was calculated by Haub (1995) at "about 105 billion births since the dawn of the human race" with a cut-off date at 50,000 BC (beginning of the Upper Paleolithic), and inclusion of a high infant mortality rate throughout pre-modern history.

The row showing total world population includes the average growth rate per year over the period separating each column from the preceding one.