What does a country’s area include?
An area figure needs a definition as well as a number. Land, inland water, islands and the boundary used for measurement can change the answer. This site uses one consistent map-derived estimate for its comparisons.
The number used on this site
Our map measures the polygons in its Natural Earth 1:50m country file on a sphere with a mean radius of 6,371.0088 kilometres. It calculates each area from the original boundary coordinates, before simplifying the outlines sent to your browser. Polygon holes are subtracted. The result is a boundary-derived estimate in square kilometres, converted to square miles when requested.
The method gives every mapped place a comparable number under the same rules. It is not an official national statistic. The source geometry does not mark every lake, coastline or small island with the detail needed to consistently separate land from inland water.
Three different measurements
| Term | What it measures | Used for our comparisons? |
|---|---|---|
| Land area | Land within the stated borders and coastline, excluding inland water such as lakes and rivers. | No |
| Total surface area | Land plus inland water within the stated country boundary; usually excludes offshore territorial waters. | No |
| Boundary-derived area | Area enclosed by the polygons in a named map dataset, with any polygon holes subtracted. | Yes |
The UN Statistics Division defines total surface area as land plus inland waters. Its land-use guidance distinguishes that total from offshore territorial waters. A statistics source may also apply its own border, date and measurement method.
Brazil shows why a label matters
Our Brazil polygon measures 8,499,361 km². For 2023, the World Bank’s FAO-sourced series reports 8,510,420 km² of surface area and 8,358,140 km² of land area, a difference of 152,280 km². Our map estimate is a third measurement. The numerical difference between it and either published figure should not be assigned to one cause without a detailed boundary comparison.
Brazil is a clear example, yet the issue becomes more consequential for countries with large lakes, many islands, complex coasts or disputed boundaries. For a close comparison, check whether both figures use the same definition, year and source.
Why two sources can disagree
- Water: a lake can be included in a total-area figure, excluded from a land-area figure, or represented differently in a polygon file.
- Coastlines and islands: a world map simplifies detail. Smaller islands may be omitted or represented with fewer points.
- Boundaries: sources can differ in how they depict disputed places, overseas territories and changes over time. Natural Earth uses de facto boundaries by default.
- Calculation: a spherical polygon estimate and a survey or ellipsoidal calculation need not produce the same number.
Natural Earth’s 1:50m countries documentation explains its cartographic scope and boundary convention. The map and our area index use the same prepared feature file.
How to use a comparison responsibly
For a quick visual question, compare two places within this site: the area method is consistent and the ratio is calculated from those two estimates. For a report that needs an official land or total-area statistic, use the relevant statistical source and name its definition and year. When the two places are nearly tied, a different definition or boundary may change their order.
Suggested citation wording: “Approximate boundary-derived areas calculated by Real Country Size from Natural Earth 1:50m Admin 0 countries geometry; figures are not official land or total-area statistics.” The method and source notes describe the map file and its limits in more detail.