MGRS Grid Overlay
MapGridder overlays a live MGRS (Military Grid Reference System) grid on an interactive map, so you can read a grid reference for any point as you pan and zoom. MGRS divides the Earth into 6 degree by 8 degree zones, then into 100km squares and metric sub-grids down to 1 meter, giving one short code for a precise square anywhere on the planet.
What you can do
- Live MGRS grid that stays aligned while you pan and zoom
- Precision from 100km squares down to 1 meter
- Grid-square labels for fast cell referencing
- Works on desktop and mobile, nothing to install
MGRS precision from 100 km to 1 m
An MGRS reference grows by one digit pair for every tenfold step in precision. The grid zone and the two-letter 100 km square come first. Every pair of digits after them, one for easting and one for northing, narrows the square by ten. The table reads one point, Druid Arch in Canyonlands National Park, Utah, at each precision.
| Reference | Digits | Square size | Pins down |
|---|---|---|---|
| 12S XH | 0 | 100 km | South-east Utah around Canyonlands, the area of one 1:250,000 sheet |
| 12S XH 0 1 | 2 | 10 km | The Needles district of the park |
| 12S XH 02 16 | 4 | 1 km | Elephant Canyon, one grid square on a 1:50,000 map |
| 12S XH 023 162 | 6 | 100 m | Druid Arch itself |
| 12S XH 0232 1625 | 8 | 10 m | The base of the arch |
| 12S XH 02322 16257 | 10 | 1 m | A survey mark at its foot |
Worked example: Druid Arch, 38.0883 N, 109.8332 W, is 12S XH 0232 1625 at 10 m precision.
- 12S is the grid zone, XH the 100 km square.
- 0232 is the easting: 2,320 m east of the square's south-west corner.
- 1625 is the northing: 16,250 m north of it.
- Four digits each side name one 10 m square.
- Need 100 m? Drop the last digit on each side: 12S XH 023 162.
- Never round. Truncate, so the digits you keep still name the square the point is in.
MGRS map maker: build a map with the grid on it
Open the map, switch the grid to MGRS, choose the precision and pan to your area. The grid redraws as you move, and from there it works as an MGRS map generator for the field: export the view as a PDF at a real scale such as 1:25,000 or 1:50,000 with the grid lines and labels printed, add symbols and routes on top of the grid, or save the map to your account and share it by link. Nothing to install and no GIS software to learn.
Frequently asked questions
What is an MGRS grid overlay?
It is a grid drawn on top of a map using the Military Grid Reference System. Each line marks an MGRS boundary, so you can give or read a grid reference like 30U XC 9931 1016 directly from the map.
Is the MGRS grid overlay free?
Yes. Overlaying the grid runs in your browser with no login and no install. A quick, free sign-in is only needed to export or to save maps to your account. Personal and non-commercial use is free; commercial use needs a paid license.
How accurate is the grid?
You can set precision from 100km squares down to 1 meter. At 1m precision a reference pinpoints a single square meter.
Can I use it on my phone?
Yes. The map and grid work in mobile browsers, and the grid redraws as you pan and zoom.
Can I use the MGRS grid for milsim or airsoft?
Yes. The MGRS grid suits milsim and airsoft well: call out objectives and rally points by grid square, coordinate fire-team movements, and keep the whole element on one reference. Pair it with tactical symbols to mark units and control measures.
How do I read an MGRS grid reference?
Read the grid zone and 100km square first (for example 30U XC), then the easting and northing digits. More digit pairs mean finer precision, from a 100km square down to a single meter.
Does the grid work offline?
The grid math runs in your browser, but the basemap tiles load over the network, so an internet connection is needed to see the map underneath.
Related: MGRS in Google Maps and Google Earth · Map grid references guide · Convert lat/long to MGRS · Map symbols (SAR, tactical, hiking) · Free MGRS grid overlay guide · Build an SFAS land nav practice lane · MGRS plotter: see a list of grids on a map