Military & Geographic Coordinates to GPS
Convert Portuguese Military Coordinates to GPS
Convert Portuguese military and geographic X/Y coordinates into GPS latitude and longitude. View any verified location on an interactive map or open it directly in Google Maps.
- Official DGT transformation grids
- Processed in your browser
- Verified against PROJ and the DGT service
Three steps
01
Enter X and Y
Type the values exactly as written; a comma or a dot as decimal separator both work.
02
Choose the system
Pick the system named on your map or document. Not sure? Use the identification helper.
03
Check on the map
Verify the point, copy the GPS coordinates or open them in Google Maps.
Why the coordinate system matters
The example values X = 186878.12 and Y = 13299.48 are just numbers until you know their coordinate system. Converted (at build time, with the same engine) under each system, they point to very different places:
| Source coordinate system | Latitude | Longitude | Where it falls |
|---|---|---|---|
| Portuguese Military Grid — Datum Lisboa / Hayford-Gauss (EPSG:20790) DGT NTv2 grid (official) | 37.085387 | -8.280686 | mainland Portugal |
| PT-TM06 / ETRS89 (EPSG:3763) No datum shift (equivalent to WGS84) | 39.767545 | -5.952157 | Outside Portugal |
| Datum 73 / Hayford-Gauss (EPSG:27493) DGT NTv2 grid (official) | 39.767581 | -5.952208 | Outside Portugal |
| Datum Lisboa / Hayford-Gauss (EPSG:5018) DGT NTv2 grid (official) | 39.767569 | -5.952200 | Outside Portugal |
| ETRS89 / UTM zone 29N (EPSG:25829) No datum shift (equivalent to WGS84) | 0.120179 | -11.812815 | Outside Portugal |
Only one of these lands in Portugal (in the Algarve), which makes the military grid a plausible reading of this example — but a plausible location is not proof. Always confirm the coordinate system from the map legend or document.