This article lists current estimates of the world population in history. In summary, estimates for the progression of world population since the Late Middle Ages are in the following ranges:
| Year | 1400 | 1500 | 1600 | 1700 | 1800 | 1900 | 2000 | 2100 |
|---|---|---|---|---|---|---|---|---|
| population (in billions) |
0.35–0.40 | 0.43–0.50 | 0.50–0.58 | 0.60–0.68 | 0.89–0.98 | 1.56–1.71 | 6.06–6.15 | c. 10–13 |
| growth p.a.[1] | >0% | <0.12% | 0.15–0.3% | 0.1–0.15% | 0.3–0.5% | 0.5–0.6% | 1.3–1.4% | 0.7–0.8% |
Estimates for pre-modern times are necessarily fraught with great uncertainties, and few of the published estimates have confidence intervals; in the absence of a straightforward means to assess the error of such estimates, a rough idea of expert consensus can be gained by comparing the values given in independent publications. Population estimates cannot be considered accurate to more than two decimal digits; for example, the world population for the year 2012 was estimated at 7.02, 7.06, and 7.08 billion by the United States Census Bureau, the Population Reference Bureau, and the United Nations Department of Economic and Social Affairs, respectively, corresponding to a spread of estimates of the order of 0.8%.
- ^ range of estimates for average growth rates over the preceding century according to the data cited under #Historical population; The average growth rate for the 14th century is low as a consequence of the Black Death.