Reference

Geolocation Precision

Latitude/longitude and other geolocation systems can express a position at exponentially increasing precision as you add digits or levels. Below are tables of the approximate ground precision of several coordinate systems.

One degree of latitude is roughly constant everywhere (~111 km), but one degree of longitude shrinks toward the poles as the meridians converge, scaling with the cosine of the latitude. For the latitude/longitude systems below, the east/west distance is therefore given at several latitudes. Grid systems like H3, S2, Geohash, and Plus Codes are designed to be nearly uniform across the globe, so their precision is instead given as an approximate cell edge length and area.

Degrees with decimals (Degrees)

Degrees-minutes-seconds (DMS)

Geohash (base32)

Each geohash character adds 5 bits, alternating between longitude and latitude, so cells are square at odd lengths and 2:1 (wider than tall) at even lengths.

Plus Codes (Open Location Code)

H3 hexagonal geospatial indexing

S2

UTM (Universal Transverse Mercator)

UTM projects each of 60 longitudinal zones (each 6° wide) onto a flat grid and expresses a position as an easting/northing in meters within the zone. Because the coordinate is already metric, the precision is simply how many digits of the easting/northing you keep.

MGRS (Military Grid Reference System)

MGRS is a grid-based alphanumeric encoding built on UTM (and UPS at the poles): a grid-zone designator, a 100 km square identifier, then equal numbers of easting and northing digits. Each added digit pair narrows the cell tenfold.

Maidenhead locator system

Used by amateur-radio operators, Maidenhead alternates letter and number pairs (field → square → subsquare → …) to encode longitude and latitude. Cells are 2:1, wider than tall, because longitude spans 360° against latitude’s 180°.