How to use it
- Type coordinates: decimal degrees (38.8895, -77.0352), degrees and minutes, or degrees, minutes and seconds with N/S/E/W.
- Or paste an MGRS reference, with or without spaces.
- Choose the precision for the output. Read the MGRS reference, the coordinates and the UTM position.
How it works
The point is first converted to UTM on WGS84: a zone number of 6° of longitude, a latitude band letter of 8° and the easting and northing in metres. Then:
- the column letter comes from the hundreds of kilometres of easting, from a set of eight letters that depends on the zone (A–H, J–R or S–Z);
- the row letter comes from the hundreds of kilometres of northing, counted in a cycle of 20 letters (A–V without I and O) that starts five letters later in even zones;
- the remaining metres of easting and northing are written with 5 digits each, truncated to the chosen precision.
Reading MGRS goes the other way: the 2,000 km cycle of row letters is resolved with the latitude band.
Worked example
38.8895° N, 77.0352° W:
- UTM zone 18, band S: easting 323,486.74 m, northing 4,306,483.05 m;
- zone 18 uses columns S–Z, and 3 hundred km gives U; 43 hundred km of northing in an even zone gives J;
- the rest is 23,486 m and 06,483 m.
MGRS at 1 m: 18S UJ 23486 06483, at 100 m: 18S UJ 234 064.
Tips
- Always give the grid zone: the same square letters repeat in every zone.
- Shorten by cutting digits from the end of each half, never by rounding: 23486 06483 → 234 064.
- Between 80° S and 84° N only; near the poles the UPS grid is used instead.