What is MGRS?
The Military Grid Reference System (MGRS) is the coordinate system used by NATO armed forces worldwide. Unlike ordinary GPS coordinates — which consist of latitude and longitude in decimal degrees — MGRS works with a grid division of the earth that is more intuitive in the field.
How does it work?
An MGRS coordinate consists of three parts: the UTM zone (a number from 1–60 and a letter), the Grid Zone Designator (two letters indicating a 100×100 km square), and the numeric coordinates that determine precision. A full 10-digit coordinate such as 31U ET 12345 67890 provides an accuracy of 1 metre.
Precision levels
- 2-digit (e.g. 31U ET 1 6) — 10 km precision
- 4-digit (e.g. 31U ET 12 67) — 1 km precision
- 6-digit (e.g. 31U ET 123 678) — 100 metre precision
- 8-digit — 10 metre precision
- 10-digit — 1 metre precision
Why MGRS is better for operational use
Decimal degrees such as 52.3676° N, 4.9041° E are difficult for people to memorise and communicate over radio. MGRS codes are shorter, more consistent, and less prone to reading errors. Furthermore, the grid is rectangular, which simplifies distance calculations.
MGRS in MilMap
MilMap fully supports MGRS in all parts of the application. You can search for locations by MGRS coordinate, enter waypoints in MGRS format, and all PDF exports automatically include MGRS coordinates per point. You can choose which coordinate format is displayed for each map.
Conversion
MilMap automatically converts between MGRS, WGS84 decimal degrees, and other common formats. This lets you collaborate with people who use different systems without having to convert manually.