Data Sources & Methodology

Every coordinate, distance, and conversion on this site is either sourced from a documented public dataset or computed with a published algorithm. This page describes exactly where the data comes from and how the numbers are produced, so you can judge how far to trust them.

City & country coordinates

The 5,944 city pages and 244 country pages are built from the GeoNames gazetteer (the cities15000 dataset, covering places with a population of roughly 15,000 or more), used under its Creative Commons Attribution license. GeoNames coordinates mark a representative central point of each city — typically the historic or administrative centre — not a centroid of the city's boundary. Population figures are GeoNames estimates and can lag official censuses by several years; treat them as approximate.

A country's reference coordinate is the coordinate of its most populous listed city, which is why it can differ from the geometric centre you may see elsewhere.

Datum & coordinate formats

All coordinates are expressed in the WGS84 datum — the reference system used by GPS, Google Maps, and OpenStreetMap. Format conversions are computed in the browser with open, documented algorithms:

DMS / DDM: exact arithmetic conversion between decimal degrees and degrees-minutes-seconds; no rounding beyond the displayed precision.
UTM: the Snyder transverse Mercator series expansion on the WGS84 ellipsoid, accurate to well under a metre within a zone.
Plus Code: Google's reference Open Location Code encoding algorithm.
Geohash: the standard base-32 binary subdivision encoding at 9-character precision (roughly ±2.4 m).

Distances, bearings & sun times

Distances between points use the haversine great-circle formula on a spherical Earth (radius 6,371 km), which is within about 0.5% of the true ellipsoidal distance — fine for city-to-city figures, not for surveying. Bearings are initial great-circle azimuths. Sunrise and sunset times on city pages are computed with the standard solar-position equations (the same simplification of Meeus used by most astronomy libraries) and are accurate to within a few minutes; atmospheric refraction is assumed at the standard −0.833°.

Search, maps & elevation

Address search: geocoding is provided by Nominatim, built on OpenStreetMap data. Accuracy depends on OSM coverage in your area.
Elevation: the elevation finder queries the Google Elevation API live for each lookup and reports the dataset resolution alongside the reading. Elevation values are not stored.

Editorial policy for place pages

City pages combine the GeoNames record with facts computed directly from the coordinates (distances to nearby cities, sunrise and sunset, UTC offset, antipode). Where a page carries additional descriptive text, it is reviewed before publication. We deliberately keep pages that add nothing beyond the raw record out of search-engine indexes, and we no longer run any automated daily rewriting of page content — changes to how pages are generated are recorded in the changelog.

Reporting errors

Spotted a coordinate that looks wrong? The upstream fix usually belongs in GeoNames or OpenStreetMap, but we want to know either way — email hello@latlongfinder.net with the page URL and the correction, and we'll verify it against the sources above.