The complete dataset
3,222 records covering the 50 states, District of Columbia, and Puerto Rico. Source: 2026 Census Gazetteer, retrieved September 27, 2026.
What is included?
- Five-digit Census GEOID, official county-equivalent name, state name and abbreviation.
- Original ALAND and AWATER measurements in square meters, plus Census-published square miles.
- Total square miles, calculated by adding the published land and water figures.
- National and state land rankings, calculated from original square-meter values.
- Representative latitude and longitude; these are internal points, not boundary coordinates.
Spreadsheet tip: import GEOID as text so leading zeros are preserved. A GEOID such as 01001 must remain five characters. JSON preserves these identifiers as strings.
Data dictionary: the columns in your download
The CSV contains one row per county equivalent and the fields below, in this order. The JSON contains a counties array plus source metadata and definitions; its records also include slug and stateSlug for constructing profile links. Area fields are numbers, while identifiers remain strings.
| Field | Type / unit | Meaning and use |
|---|---|---|
geoid | Five-character text | County-level identifier, including the two-digit state code. Preserve leading zeros. |
name | Text | Official county-equivalent name, including designations such as parish, city, or municipio. |
state | Text | State, district, or territory name. Use alongside county names in reader-facing tables. |
stateCode | Two-character text | USPS abbreviation, such as TX, DC, or PR. |
landSqM | Integer m² | Original Census ALAND. This is the field used for exact land rankings. |
waterSqM | Integer m² | Original Census AWATER. Add to ALAND to reproduce the total-area ordering. |
landSqMi | mi² | Census-published land square miles, retaining three-decimal source precision. |
waterSqMi | mi² | Census-published water square miles. A rounded zero can mask a positive square-meter value. |
totalSqMi | mi² | Land plus water square miles, rounded to three decimals. |
nationalLandRank | Integer position | Descending original land area across all records. Exact ties sort by GEOID ascending. |
stateLandRank | Integer position | The same land ordering within the state-level jurisdiction. |
latitude | Decimal degrees | Census internal-point latitude; not a boundary, an address, or necessarily a county seat. |
longitude | Decimal degrees | Census internal-point longitude. Do not interpret this point as the county’s extent. |
populationBase2020 | Integer persons | Census Bureau April 1, 2020 estimates base, the starting point for the annual estimates. |
population2025 | Integer persons | Census Bureau July 1, 2025 resident population estimate (Vintage 2025). Estimates are revised annually. |
densityPerSqMi | Persons per mi² | population2025 divided by landSqMi, rounded to one decimal. Recalculate from the two source fields for exact work. |
countySeat | Text | Current county seat or seats from Wikidata (CC0), separated by semicolons. Empty for independent cities, census areas, and others without a seat. |
wikidataId | Text | The Wikidata item matched by FIPS code, for joining further community-maintained facts. |
A reliable first import
- Use your spreadsheet’s CSV import command and explicitly set
geoidto text. Check that01001still has five characters. - Confirm 3,222 records excluding the header and one record per GEOID. Keep the original download before changing any values.
- Sort the entire table by
landSqMdescending andgeoidascending to reproduce national land order. Sorting only one column would detach numbers from their counties. - Calculate water share as
waterSqMi / totalSqMiand format the result as a percentage. Do not multiply by 100 as well as applying percentage formatting.
Filtering to a state does not recalculate nationalLandRank; use stateLandRank for that comparison. For a custom subset, compute and label a new rank. The complete spreadsheet workflow includes spot checks, tie handling, and join diagnostics.
Before combining this with another dataset
Match the geographic level and boundary vintage as well as the identifier. Population and housing counts are not included in the Gazetteer or this download. Obtain those from an appropriate source and check compatibility before calculating a rate. Connecticut’s current planning regions, for example, cannot simply inherit the population of similarly located historical counties.
A county-level average does not describe every neighborhood, and an internal coordinate is not a geocoding service. Read the density denominator guide before joining population, and use suitable detailed boundary data for spatial analysis. These are separate tasks from comparing the official area fields.
Suggested citation
For the underlying measurements, cite the Census Bureau. If you use our rankings or conversions, cite US County Area as the transformation source too.
U.S. Census Bureau. 2026 Gazetteer Files: Counties, national file. Retrieved September 27, 2026. US County Area, county area conversions and rankings, https://uscountyarea.com/.
Measurement definitions and ranking rules · Census Gazetteer documentation ↗
Reuse and limitations
US County Area’s additions to the downloadable CSV and JSON datasets, including normalization and calculated rankings, and its generated county-outline and locator SVGs are available under Creative Commons Attribution 4.0 International (CC BY 4.0). You may copy, adapt, and redistribute these additions, including commercially, with attribution, a license link, and an indication of changes. Cite US County Area and the U.S. Census Bureau, and retain the source vintage. Download the scope and attribution statement.
This license covers the publication’s contributions to those data and map files; it does not claim ownership of underlying Census measurements or change any source rights. Editorial articles, the logo, and other brand images are outside this data license. A ranking is relative to the geography included in this release. These data and generalized maps do not establish legal property boundaries.
Reproducibility
The downloaded Census ZIP had this SHA-256 checksum:
6a99ca00efbc0be5112e225d4102704c51d5ce3b16e3afd6e4159460595fd12aCounty outlines use a separate 2025 cartographic boundary source. They are illustrations and are not used to calculate the 2026 measurements.