County Maps US

Tools Coordinates

GPS Coordinate Converter

Paste a coordinate in any format and every other format is filled in. The point is also placed on the map so a typo is visible at once.

How to use it

  1. Paste the coordinate. The format is detected: decimal degrees, DMS, DDM, UTM ("17T 630084 4833438" or "17 N 630084 4833438"), MGRS ("17TPJ 30084 33438"), geohash or Plus Code.
  2. Press Convert or Enter. All the other formats are listed with copy buttons and the point is pinned.
  3. Drag the pin to move the point; every format updates.

How it works

Everything runs in the browser. Detection tries the formats in order from most specific (MGRS, UTM, Plus Code) to least (decimal pairs), and the detected format is named so a misread is obvious. UTM and MGRS use the Transverse Mercator series on the WGS84 ellipsoid with sub-metre accuracy between 80 degrees south and 84 degrees north; outside that band UTM is not defined and those rows are left blank.

Geohash and Plus Code are cell codes, not points, so decoding one returns the centre of its cell. A 9-character geohash cell is about 5 m by 5 m and an 11-character Plus Code cell about 3 m by 3 m.

Questions

How does it tell UTM from a coordinate pair?
UTM has a zone number followed by a band letter or hemisphere, then two large integers (easting under 1,000,000, northing under 10,000,000). A decimal pair has two numbers within 90 and 180. A bare pair of six-digit numbers without a zone is not enough and the tool asks for the zone.
Is the converted point exactly the same place?
For DD, DMS and DDM, yes to the precision shown. UTM and MGRS conversions are within a millimetre of the reference algorithm. Geohash and Plus Codes round to their cell size.
What datum is used?
WGS84 throughout, which is what GPS receivers, phones and web maps use. Coordinates from older paper maps on NAD27 or ED50 can differ by up to a few hundred metres and are not shifted here.

All map tools, free and without an account. Location data is processed in your browser and by the open geocoding services named on the sources page; nothing is stored by this site.