GennyPop combines UN population projections with a simple simulation to illustrate how populations change. These are estimates, not real-time counts of individual people.
- Starting population: We use the UN World Population Prospects 2024 medium projection for 1 July 2026, with a worldwide total of 8,300,678,396 people.
- Population by generation: The UN provides world population totals in five-year age groups. We spread each group approximately across individual ages and birth years, then total the birth years assigned to each generation. For the open-ended 100+ group, we use an approximate age distribution. The UN does not publish official counts for Gen X, Millennials or the other generation labels.
- Births and deaths: The simulation uses approximately 132.5 million births and 63.64 million deaths per year (about 4.2 births and 2.0 deaths per second). Births are added to the current birth-year cohort; deaths are distributed across existing cohorts using approximate age-related weights.
- Live counters: The page recalculates estimated population from the 2026 starting point and the elapsed time. “World change since opening” compares the estimated total now with when you loaded the page. The separate births and deaths counters estimate events since you opened this page and reset when you refresh.
Estimated population = starting population + estimated births − estimated deaths
Important: The numbers update each second, but this is not a live UN feed or a census. Births, deaths and generation sizes are modelled; real-world rates change over time and the totals may differ from later UN projections. Figures for future generations are illustrative.
Source: United Nations — World Population Prospects 2024 (medium variant). The UN data are used as a baseline; the generation groupings and moving counters are GennyPop calculations.
