Evidence before interpretation
Data sources and method
Atlas Compare compares land area and population, then calculates density from those cited inputs. Each source and data year stays beside its value so the comparison can be checked.
Geographic coverage
The U.S. set contains all 50 states plus Washington, DC, which is labeled as a district rather than a state. The country directory contains 196 source-supported profiles grouped into six inhabited continents, plus an Antarctica scope page. Coverage follows the bundled statistical series and matched map outlines; it is not a claim that every territory or disputed entity is represented.
The State of Palestine and Taiwan use separately identified statistical supplements. Dependent territories are not listed as separate country profiles. Western Sahara is omitted because the staged sources do not provide a complete paired area and population record; Kosovo is omitted because the staged World Bank series and M49 scope do not provide a complete comparable record. The country directory makes these gaps visible.
UN M49 is used as a statistical region reference, not as a statement about political identity or sovereignty. The map source and the country names likewise do not settle legal status.
Sources used
- U.S. state population2025 estimates from the U.S. Census Bureau Population Estimates Program.Census 2025 state estimates file
- U.S. state land areaLand area in square miles from the 2026 Census Bureau Gazetteer files.2026 State Gazetteer download
- U.S. state boundariesCensus TIGER/Line 2025 state boundary data, drawn for comparison rather than legal or navigation use.TIGER/Line files
- Country populationWorld Bank indicator SP.POP.TOTL. The latest non-empty year in the stored series is preserved for each country.Population, total
- Country land areaWorld Bank indicator AG.LND.TOTL.K2, in square kilometres. Each place page shows the year attached to its stored value.Land area
- Country boundariesNatural Earth Admin 0 country boundaries, 1:10m, version 5.1.1.Natural Earth country download
- International first-level region mapsNatural Earth — Admin 1 states and provinces, 1:10m, version 5.1.1. The current map index contains 145 countries and 3,642 named divisions across Africa, Asia, and Europe. Natural Earth describes its Admin 1 layer as beta; coverage and hierarchy vary. South Sudan and the State of Palestine have no matching divisions in this snapshot.Natural Earth Admin 1 source
- Vatican City supplementOfficial Vatican City State pages report an area of 0.44 km² (without a measurement year) and 882 residents on a page last modified in August 2026. These values are not World Bank observations.Vatican City State geographyVatican City State population
- Country names and regionsUN Statistics Division M49 country and area classifications, cross-checked against Natural Earth identifiers. Region labels are statistical groupings.UN M49 overview
The bundled World Bank series are a dated snapshot prepared on 26 September 2026. Public statistical series may be revised; an observation year and the snapshot date are not the same thing.
How calculations work
- Population density: population ÷ land area in square kilometres. For U.S. states, square miles are converted using 1 sq mi = 2.589988110336 km².
- Area ratios: source units are converted to square kilometres before comparison.
- Metric bars: the longer value sets each row's 100% width. Values remain printed alongside the bars.
- Map outlines: state and country boundaries use the same Equal Earth projection. Each outline keeps its shape; one common pair scale preserves the area ratio, even when one place becomes very small.
- Regional outline area: the region explorer calculates an approximate spherical polygon-area estimate from generalized map geometry using a mean Earth radius of 6,371,008.8 metres. This is not a current official land-area measure.
Country population and land area can come from different years. The page shows both source years and labels density as calculated; it is not a separately sourced measurement.
International regions: what is and is not comparable
Admin 1 units have country-specific names and do not share one universal boundary hierarchy. The site uses Natural Earth for reference maps and lists; it does not present these outlines as a current official register. The available map geometry does not supply regional population, income, literacy, school attendance, infant mortality, or income-distribution figures. Those measures will be added only where a comparable, dated source can be verified for the same division definitions.
Accordingly, the regional comparison control compares approximate outline-derived area estimates only. It does not calculate rankings or a composite score. Review the region coverage directory for per-continent counts and country-level gaps.
City data publication standard
City comparisons are not available yet. Before any city measure is shown, the record must identify its exact geography, boundary vintage, source publisher and direct link, observation or effective date, definition, and important limitations. If the two sides do not describe comparable units, we will not present them as a like-for-like comparison.
Potential topics—including reproductive-rights, alcohol, and cannabis rules; public-school indicators; cost-of-living measures; minimum wage; and federal or local representation—remain under source review. They would be descriptive facts only, with the responsible jurisdiction and relevant dates made explicit; we will not turn them into a composite score, a “best place” ranking, or personal advice.
Read the city comparison evidence framework for the planned geography and publication checks.
Plain-language guides to the measures
Use these explainers alongside the source labels and reference periods on each profile:
Limits
Boundary files generalize coastlines and jurisdiction shapes. Area values can use definitions that do not perfectly match the map boundary. Small places can be difficult to see beside a much larger one, so the cited metrics and text calculation remain the definitive comparison.
This is general reference information, not personalized legal, financial, education, health, safety, or relocation advice. Facts do not determine whether a place is suitable for an individual, and no location is recommended.