Data & accuracy
Where Guess the Real Size’s country outlines and estimated areas come from, what is included, and how the display is checked.
Estimated from the game’s maps
Guess the Real Size uses Natural Earth 1:50m Admin 0 Countries, version 5.1.1, from the ne_50m_admin_0_countries layer. Both outlines and answer areas come from those same records. The question bank version is 2026-10-14.v1; scoring uses area-log-v1.
These are estimates from a generalized map dataset, not official land-area statistics or precise national territory measurements. Small islands and boundary details omitted by the source cannot be reconstructed by the game.
What is included
The current bank covers Austria, Botswana, Bulgaria, Czechia, Germany, Hungary, Paraguay, Poland, Romania, Slovakia, Uruguay, and Zambia. Each country is matched to its own country record; records for overseas territories or dependencies are not merged into it.
All polygon parts, islands, and holes present in each chosen source record are retained. This batch has 17 polygon parts and no interior holes: Germany has six parts and the other countries one each.
We use the ordinary countries layer, not the “without boundary lakes” alternative, and do not separately subtract lakes. Water inside a source polygon counts toward its area; water outside that boundary does not. This is why the result must not be described as official land area.
Checking area and display consistency
We calculate surface areas on the WGS84 ellipsoid, project the same geometry with an equal-area projection, and simplify the display outlines while preserving their parts. Final outlines are checked by filled area; border thickness is excluded.
The internal acceptance limit is 1% at each stage and for every question’s displayed answer ratio. In this bank, the largest simplification area difference before calibration is about 0.03%, and the final pair-ratio difference is below 0.00001%. These checks compare our own processing stages. They do not establish accuracy against official country areas or the real world.
At the start, B is normalized to the displayed area of A. Changing your guess changes B’s area, not merely its width. Revealed answers use a common scale for both outlines.
Review status and corrections
The dataset and its 20 question pairs have passed development checks for geometry, area ratios, duplicate pairs, and the allowed answer range. These checks verify the game’s processing and do not establish accuracy against official national statistics.
To identify a suspected data issue, note the two countries, your guess, the shown answer, and question-bank version. Changes to boundaries or answers require a new question-bank version.