Intro
Military Grid Reference System (MGRS) is an alphanumeric grid-based coordinate system based on UTM
Structure of MGRS Coordinates
A MGRS coordinate has the following components:
- Grid Zone Designator (GZD): Combines a UTM Zone number (1–60) with a Latitude Band (C–X, omitting I and O)
- 100 km × 100 km Grid Square Identifier: Two letters (e.g., WL) that identify a specific 100 km × 100 km square within the GZD
- Easting and Northing (Numerical Portion): The number of digits determines precision: 1 m, 10 m, 100 m, 1 km, or 10 km
For example:
17S PU 12345 67890 identifies a precise location within a 100 km square in zone 17S.
Grid Zone Designators (GZD):
Grid Square Identifiers:
Reading an MGRS Coordinate
UTM:
768000 E
4388600 N
MGRS:
10S GJ 068 446
Tip
The two-letter 100 km grid square identifies a specific 100 km × 100 km square within a UTM zone. Once that square is known, only the remaining Easting and Northing within the square need to be specified.