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Sources & attribution

Where every number comes from, and the licence it is used under.

Primary source

United Nations, Department of Economic and Social Affairs, Population Division (2024). World Population Prospects 2024.

All population figures, projections, median ages, fertility rates, life expectancy and age structures on this site are derived from WPP 2024, using the Estimates (1950–2023) and the Medium, Low and High projection variants (2024–2100). Age-structure pyramids use the “Population by 5-year age groups” dataset.

Exactly which files

Three files from the WPP 2024 download page, processed on 2026-06-15:

  • WPP2024_Demographic_Indicators_Medium.csv: Estimates 1950-2023 and the medium projection 2024-2100: population, births, deaths, growth rate, median age, fertility, life expectancy, net migration, density.
  • WPP2024_Demographic_Indicators_OtherVariants.csv.gz: The low and high fertility variants, used for the shaded band on country charts.
  • WPP2024_PopulationByAge5GroupSex_Medium.csv.gz: Population by five-year age group and sex, used for the age pyramids.

Population is read from the TPopulation1Jan field throughout, so every figure on this site refers to 1 January of the year given. The UN publishes it in thousands; we multiply by 1,000 and store whole people. We never mix that field with the 1 July series. Countries, territories, regions and the world aggregate are kept separate, so a region is never summed alongside its own member countries.

The full field-by-field mapping, including every transformation applied, is in the data contract, and npm run verify in that repository reproduces the site’s benchmark figures from the processed data.

How often this updates

When the UN publishes a new revision we download it, re-run the import, check the output and deploy. That is a manual process, not an automatic feed: nothing here polls the UN, and a new revision does not appear on this site on its own. The revision in use right now is UN World Population Prospects 2024, processed on 2026-06-15.

Revisions move the past as well as the future, sometimes by a lot, which is why two sites on different revisions legitimately disagree. We walk through the 8 billion case, where the 2022 and 2024 revisions put the same milestone eight months apart.

Licence

The UN World Population Prospects data is made available under the Creative Commons Attribution 3.0 IGO licence (CC BY 3.0 IGO). We attribute the United Nations as the source on every page and link back to the original data. This site is not affiliated with or endorsed by the United Nations.

Download the data yourself

All of the underlying files are free to download from the UN:

Further reading

See the methodology for how we turn these sources into the charts and projections on the site.