Data Sources

Where Worldoku’s country facts come from.

Worldoku’s country data — borders, populations, memberships, languages, religion and physical geography — is compiled from the public, authoritative sources below. Figures reflect recent estimates and may change over time. Worldoku is an independent project and is not affiliated with any organisation listed here.

Country data

• United Nations
  UN membership and observer states
• UN World Population Prospects
  Country population estimates
• The World Bank
  Population and development indicators
• CIA World Factbook
  Land area, land borders, coastlines, languages, military status and physical geography
• NATO
  NATO membership
• European Union
  EU membership
• European Central Bank
  Eurozone and use of the euro
• G20
  G20 and G7 membership
• OPEC
  OPEC member states
• ASEAN
  ASEAN member states
• Ethnologue
  Official and widely spoken languages
• Pew Research Center
  Majority religion by country
• Smithsonian Global Volcanism Program
  Countries with active volcanoes
• IANA Time Zone Database
  Time zones
• WorldStandards
  Driving side (left- and right-hand traffic)
• Encyclopædia Britannica
  Deserts, rivers, mountains and general reference

Fact of the Day

The daily geography facts are drawn from these sources.

• CIA World Factbook
  Land area, borders, elevation, coastlines, capitals and general geography
• Encyclopædia Britannica
  Lakes, rivers, deserts, mountain ranges and historical facts
• National Geographic
  Natural features, rainforests and ocean statistics
• Natural Resources Canada
  Canadian lake count
• Norwegian Mapping Authority
  Norway's coastline length
• Geospatial Information Authority of Japan
  Japan's island count
• Philippine Statistics Authority
  Philippines' island count
• Statistics Finland
  Finland sauna and vehicle statistics
• UNESCO
  World Heritage Sites including Machu Picchu
• UNEP
  Lake Chad shrinkage and the Aral Sea
• Great Barrier Reef Marine Park Authority
  Great Barrier Reef dimensions
• AlpTransit Gotthard
  Gotthard Base Tunnel length
• McGovern et al. (PNAS, 2017)
  Archaeological evidence of winemaking in Georgia
• Ethnologue
  Language counts by country (Papua New Guinea)

See also our guide to debatable answers for the judgment calls behind the trickier categories.