what is the total population of the world today
World population In demographics, the world population is the total number of humans currently living, and was estimated to have reached 7.6 billion as of December 2017.[1] Estimates of the total number of humans who have ever lived range from 106 to 108 billion as of 2007.[2][3][4] Though the population is currently growing quite rapidly, future changes are influenced by difficult-to-predict factors such as economic development, cultural changes, migration, and natural disasters. Various mathematical models show that by 2100 the global population could be either rising or falling depending on how these factors affect birth and death rates.
World population estimates As a general rule, the confidence of estimates on historical world population decreases for the more distant past. Robust population data only exists for the last two or three centuries. Until the late 18th century, few governments had ever performed an accurate census. 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.[3]  Published estimates for the 1st century ("AD 1") suggest an uncertainty of the order of 50% (estimates range between 150 and 330 million). Some estimates extend their timeline into deep prehistory, to "10,000 BC", i.e. the early Holocene, when world population estimates range roughly between one and ten million (with an uncertainty of up to an order of magnitude).[4][5]
World population estimates Estimates of the "total number of people who have ever lived" is 107.6 billion as of 2011.[11] The answer naturally depends on the definition of "people", i.e. is only Homo sapiens to be counted, or all of genus Homo, but due to the small population sizes in the Lower Paleolithic, 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.[12] The estimate is more crucially affected by the estimate of infant mortalitys vs. stillborn infants, due to the very high infant mortality throughout the pre-modern period. 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 an inclusion of a high infant mortality rate throughout pre-modern history.[13]
World population There is no estimation for the exact day or month the world's population surpassed one or two billion. The points at which it reached three and four billion were not officially noted, but the International Database of the United States Census Bureau placed them in July 1959 and April 1974 respectively. The United Nations did determine, and commemorate, the "Day of 5 Billion" on July 11, 1987, and the "Day of 6 Billion" on October 12, 1999. The Population Division of the United Nations declared the "Day of 7 Billion" to be October 31, 2011.[79]