Live world population counter, country population data, historical trends from 1800, UN projections to 2100, and per-capita resource estimates. Based on UN DESA data.
Population Projection Tool
Select year and region
See population for any year from 1800 to 2100 with UN projections.
| Milestone | Year Reached | Years to Add Next Billion |
|---|---|---|
| 1 Billion | 1804 | 123 years |
| 2 Billion | 1927 | 33 years |
| 3 Billion | 1960 | 14 years |
| 4 Billion | 1974 | 13 years |
| 5 Billion | 1987 | 12 years |
| 6 Billion | 1999 | 12 years |
| 7 Billion | 2011 | 12 years |
| 8 Billion | November 15, 2022 | ~14 years (est.) |
| 9 Billion | ~2037 (projected) | ~17 years (est.) |
| Peak Population | ~2086 (projected) | ~10.4 billion (UN medium) |
| Rank | Country | Population (2026 est.) | % of World | Growth Rate |
|---|
The UN uses the cohort-component method: the population is divided into age-sex cohorts. Each year, each cohort ages, and the model applies age-specific fertility rates, mortality rates and migration assumptions to project forward. The medium, high and low variants differ mainly in their fertility assumptions.
P(t) = population at time t P(0) = base population r = annual growth rate t = years elapsed. This simplified exponential model is used for short-range estimates. Long-range projections use the full cohort-component model.
The demographic transition explains why population growth slows: as countries develop economically, death rates fall first (more food, better medicine), causing rapid growth. Later, birth rates also fall as women gain education and economic independence. Most developed nations are now near or below replacement fertility (2.1 children per woman).
These estimates use average global per-capita consumption benchmarks. Actual needs vary widely by country and lifestyle.
| Resource | Per Person Per Day | Source/Basis |
|---|---|---|
| Food (calories) | 2,500 kcal minimum | FAO recommended daily average |
| Freshwater | 50 litres for basic needs | WHO minimum for health and dignity |
| Energy | ~1.95 kWh/day (global avg) | IEA World Energy Outlook 2023 |
| Housing | ~2.5 persons per household | UN Habitat global average |