The World Population Clock is an estimate of world population size at a given moment and an indication of how fast it is growing.

The world population and vital event estimates shown in the clock are not meant to imply that these data are precisely known. Instead, these estimates are the result of an aggregation of data for individual countries and areas from the International Database (IDB) and a linear interpolation between successive midyear population data. World vital events for different units of time are computed based on the number of months, days, hours, minutes, or seconds in the given year. Additionally, figures may not add to totals due to rounding.

According to estimates and projections last revised in the vintage 2024 release of the IDB, the world population reached 7 billion in 2011 and 8 billion in 2023. Looking ahead, the world population is projected to reach 9 billion in 2038, 10 billion in 2057, and peak at 10.9 billion in 2098 before declining.

The world population estimates and projections used to produce these figures were developed by the Census Bureau based on analysis of available data on population, fertility, mortality, and international migration. The analysis was performed separately for the countries and areas of the world with populations of 5,000 or more.

Population estimates and projections are based on census, survey, vital statistics, and other data. For most countries, and especially less developed countries, adjustments to these data are necessary to correct for errors, omissions, and inconsistencies. Since the most recent data used to produce estimates for each country or area may be several years old (or much older), the population data used for the clock are projections from those estimates based on assumed trends in fertility, mortality, and migration. As new data become available, all data are reevaluated, and the estimates and projections may change.

For more information about how these country and area estimates and projections are made, see the International Database methodology statement. For explanation of the longer term trends influencing world population change, see this America Counts story on the World Population at 8 billion (note: using vintage 2023 IDB data). See also historical estimates of the world’s population.