Coordinate Converter

Formats the converter accepts

Type latitude and longitude in the two fields, in any of these forms:

For southern latitudes and western longitudes, use either a minus sign in decimal degrees (-33.8688) or the letter S or W in DMS. The result shows all three outputs: decimal degrees, DMS and UTM.

How precise do you need to be?

Each extra decimal place is ten times more precise. For latitude:

One second of latitude is about 31 m. For longitude the distances shrink towards the poles: at 50° latitude they are about two-thirds of the values above.

A consumer drone's GPS is usually accurate to a few metres, so five decimal places is enough to describe its position. Survey work with RTK corrections or ground control points needs six or more. Longer strings of digits from an app don't mean the position is that accurate.

Common mistakes that move a point by kilometres

Latitude and longitude swapped. Most apps and Google Maps write latitude, longitude. KML files, GeoJSON and many programming libraries write longitude, latitude. If a point lands in the sea or on another continent, swap them first.

A missing minus sign. At the latitude of Madrid, -3.70 and 3.70 longitude are about 630 km apart. With DMS, check the W or S letter survived copy and paste.

Minutes read as decimals. 37°30' is 37.5°, not 37.30°. Mixing the two can move a point by tens of kilometres.

UTM, and grids that look like it

UTM divides the world into 60 zones, each 6° of longitude wide, and gives positions in metres as an easting and northing within the zone. It is convenient for measuring distances on a site, which is why surveying and photogrammetry software often uses it. Always keep the zone number and hemisphere with the numbers: the same easting and northing exist in every zone.

Many countries also have their own national grids, which look similar but are not UTM:

• the Greek Grid (GGRS87, often called EGSA87);
• the British National Grid (OSGB36);
• US State Plane systems.

Pasting a national-grid coordinate into a tool expecting UTM, or the reverse, can move a point by hundreds of metres or more. If a client gives you coordinates in a national grid, convert them with a GIS program that supports that system.

The converter uses the standard 6° zones. It does not apply the special zone boundaries used around south-west Norway and Svalbard, so for those areas check the zone your other software uses.

The datum behind the numbers

All the outputs use WGS84, the reference system used by GPS and by drones. Most modern maps and apps use it or a system that differs from it by less than a metre, such as ETRS89 in Europe. Older coordinate sets, such as ED50 on older European maps and charts, can differ from WGS84 by more than 100 m. If a point from an old document doesn't line up with satellite imagery, the datum is a likely cause.

Where drone pilots use this

• Entering a take-off point or a point of interest from a client's document into your flight app.
• Checking an airspace notice: NOTAMs give positions in a compact form such as 375800N 0234300E, which you can enter here as 37 58 00 N and 23 43 00 E. See how to read a NOTAM.
• Preparing boundary points for the Area Calculator, which takes decimal degrees.
• Sharing a precise meeting point or landing zone with a team.