Online geographic coordinate conversions using the GeoConvert utility

    input   = 20.629652 -89.460594
    lat lon = 20.62965 -89.46059 (20°37'46.7"N 089°27'38.1"W)
    UTM/UPS = 16n 243588 2283102
    MGRS    = 16QBH4358883101

GeoConvert (version 2.5.2) converts between geographic (latitude and longitude) coordinates, universal transverse Mercator (UTM) or universal polar stereographic (UPS) coordinates, and the military grid reference system (MGRS). Examples of legal geographic locations are (these all refer to roughly the same place, Cape Morris Jesup on the northern tip of Greenland):

    Latitude and longitude:       MGRS:
        83.627 -32.664                24XWT783908
        W32d40 N83d37.6               YUB17770380
        83°37'39"N 32°39'52"W     UTM:
        83:37:39 32:39:52W            25n 504158 9286521
        32:39.9W 83:37.6N             430000 9290000 26n
        32:40W+0:0:6 83:37.6      UPS:
        32:40W+0:0:6 83:38-0:0.4      n 1617772 1403805

• The letter in following the zone number in the UTM position is a hemisphere designator (n or s) and not the MGRS latitude band letter. "north" or "south" can also be used, e.g., 25north.
• MGRS coordinates are taken to refer to grid squares (not to the intersections of grid lines). Thus in UTM zone 38n, the square area with easting in [444 km, 445 km) and northing in [3688 km, 3689 km) corresponds to the MGRS square 38SMB4488 (at 1 km precision).
  • When an MGRS coordinate is read, a representative point within the grid square, namely, the center, is returned.
  • The MGRS easting and northing are obtained by truncation to the requested precision (not rounding).
• Usually Output zone should be Match input or standard. If the latitude and longitude are given, the standard UPS and UTM zone rules are applied; otherwise the UPS/UTM selection and the UTM zone match the input. The other choices let you override this selection.

GeoConvert, which is a simple wrapper of the GeographicLib::GeoCoords class, is one of the utilities provided with GeographicLib. This web interface illustrates a subset of its capabilities. If you wish to use GeoConvert directly, download and compile GeographicLib.