Lambert 93 ↔ GPS (WGS84) Converter
Convert Lambert 93 (RGF93, EPSG:2154) coordinates to GPS latitude/longitude and back — the official projected system for mainland France.
Lambert 93 is the official projected coordinate system of metropolitan France, built on the RGF93 datum and registered as EPSG:2154. Instead of degrees of latitude and longitude, it gives a position as an X (easting) and Y (northing) in metres — the form used by IGN maps, the cadastre and most French GIS files.
Because RGF93 is aligned with the global WGS84 frame used by GPS, a Lambert 93 coordinate and its GPS equivalent describe the same spot to within a few centimetres. As a quick check, Lambert 93 values are large positive numbers: X around 650,000 and Y around 6,800,000 for a point near Paris.
Enter an X/Y pair on the converter to read the GPS position and address, or enter a latitude/longitude to get the Lambert 93 coordinates. You need this whenever you handle official French data — a cadastral parcel, an IGN export or surveyor coordinates.
Frequently asked questions
What is Lambert 93?
Lambert 93 (EPSG:2154) is the official projected coordinate system for mainland France, based on the RGF93 datum. It expresses positions as X/Y in metres rather than latitude/longitude in degrees.
What is the difference between Lambert 93 and GPS (WGS84)?
WGS84 is the global GPS system in degrees of latitude and longitude; Lambert 93 is a flat projection in metres for France. Because Lambert 93 uses the RGF93 datum, aligned with WGS84, they describe the same point to within centimetres.
How do I recognise Lambert 93 coordinates?
They are two large numbers in metres: X (easting) roughly 100,000–1,300,000 and Y (northing) roughly 6,000,000–7,200,000 for metropolitan France.