BYTETOOLS

MGRS Coordinate Converter

Convert latitude and longitude to an MGRS grid reference and back, at 1 m to 100 km precision, with the UTM zone, band and 100 km square shown.

MGRS is the alphanumeric form of UTM used on military and topographic maps. Datum is WGS-84; the grid is defined between 80°S and 84°N.
18
UTM zone
S
Latitude band
UJ
100 km square
1 m
Square size

MGRS grid reference

18S UJ 23394 07395

No spaces: 18SUJ2339407395

Underlying UTM easting
323394.30 m
Underlying UTM northing
4307395.63 m
Input in DMS
38°53'51.72"N 77°2'11.40"W
Grid zone designator
18S

Same point at every precision

  • 1 m (5 digits each)18S UJ 23394 07395
  • 10 m (4 digits each)18S UJ 2339 0739
  • 100 m (3 digits each)18S UJ 233 073
  • 1 km (2 digits each)18S UJ 23 07
  • 10 km (1 digit each)18S UJ 2 0
  • 100 km square only18S UJ

What is the MGRS Coordinate Converter?

This MGRS converter turns a latitude/longitude pair into a Military Grid Reference System string such as 18S UJ 23394 07395, and decodes any MGRS reference back into degrees.

  • Two-way conversion between WGS-84 degrees and MGRS grid references
  • Precision from 1 m to the 100 km square, with the numeric part truncated correctly
  • Shows the UTM zone, latitude band, 100 km square letters and the raw easting/northing
  • Decoding reports both the square's south-west corner and its centre point
  • Accepts DMS input and spaces anywhere in the reference
  • Runs fully offline in your browser — coordinates are never uploaded

How to use the MGRS Coordinate Converter

  1. 1

    Pick a direction: latitude/longitude to MGRS, or MGRS back to latitude/longitude.

  2. 2

    Type your coordinates in decimal degrees or DMS, or paste an MGRS reference with or without spaces.

  3. 3

    Choose the precision you need, from 1 m (five digits each) down to the bare 100 km square.

  4. 4

    Read the grid reference, the underlying UTM zone, band and easting/northing, then copy it.

  5. 5

    Check the precision table to see the same point written at every level of detail.

About the MGRS Coordinate Converter

This MGRS converter turns a latitude/longitude pair into a Military Grid Reference System string such as 18S UJ 23394 07395, and decodes any MGRS reference back into degrees. It works out the UTM zone and easting/northing first, then derives the latitude band and the two 100 km square letters, so you can see exactly how the reference is built.

MGRS is what appears on NATO military maps, USGS topographic sheets, search-and-rescue grids and forestry plans, because one short string names a square on the ground with no minus signs and no ambiguity about which number is which. Choose 1 m, 10 m, 100 m, 1 km or 10 km precision and the numeric part is truncated to match.

Everything is computed in your browser with JavaScript — no coordinates are uploaded, logged or stored anywhere. That makes it safe for operational locations, and the page keeps working after the connection drops.

Frequently asked questions

How do you read an MGRS coordinate?

Read it in three chunks. The leading number and letter are the grid zone, such as 18S; the next two letters name a 100 km square inside it; and the digits that follow split evenly into an easting then a northing. So 18S UJ 23394 07395 is 23,394 m east and 7,395 m north of the corner of square UJ.

What is the difference between MGRS and UTM?

They describe the same position. UTM gives a zone plus a full easting and northing in metres, while MGRS replaces the leading digits with letters that name a 100 km square. MGRS is shorter to say over a radio and harder to mis-transcribe, which is why military and rescue teams prefer it.

How accurate is a 6-digit MGRS reference?

Six digits means three for easting and three for northing, which locates a 100 m square. Eight digits gets you to 10 m and ten digits to 1 m. The reference always names a square, not a point, so the true position is somewhere inside that box.

Does MGRS work at the North and South Poles?

No. MGRS is built on UTM, which is only defined between 80°S and 84°N. Beyond those latitudes the Universal Polar Stereographic grid takes over with a different lettering scheme, so this converter reports an error rather than guessing.

Which datum does this converter use?

WGS-84, the datum used by GPS and by modern NATO mapping. If your map sheet is on an older datum such as NAD27 or ED50, the same grid reference can land 100–200 m away, so check the datum note in the margin before you rely on it.

Are my coordinates sent to a server?

No. The whole conversion, including the Transverse Mercator series, runs in your browser. Nothing is transmitted or saved, so you can convert sensitive locations safely and the tool keeps working with no connection.

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