mapverter

EPSG:3857 Coordinate Converter

Convert EPSG:3857 Pseudo-Mercator coordinates in metres to WGS 84 longitude and latitude, or export SHP and CSV in EPSG:3857, right in your browser.

WGS 84 / Pseudo-Mercator

Area of use (longitude / latitude): west -180°, south -85.06°, east 180°, north 85.06°.

PROJ definition

+proj=merc +a=6378137 +b=6378137 +lat_ts=0 +lon_0=0 +x_0=0 +y_0=0 +k=1 +units=m +nadgrids=@null +wktext +no_defs
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SHP (zip, or .shp with .shx, .dbf, .prj), KML, KMZ, GeoJSON, GPX, CSV

Free · one dataset at a time · up to 20 MB

Converting several datasets at once?

Mercator on a sphere

EPSG:3857, WGS 84 / Pseudo-Mercator, applies the Mercator projection to WGS 84 longitude and latitude using a sphere with a radius of 6,378,137 m instead of the ellipsoid. Coordinates are in metres, measured from the point where the equator meets the prime meridian, with no false easting or northing. The area of use stops at 85.06° north and south.

In an ESRI-style .prj, it is named WGS_1984_Web_Mercator_Auxiliary_Sphere. mapverter recognizes that definition by its parameters, as well as .prj files that carry the EPSG code.

Recognizing EPSG:3857 values

The numbers run into the millions. The point at 127° E, 37.5° N, for example, is about x = 14,137,575 m and y = 4,509,031 m. If a file without a .prj has values like these, the English interface lists EPSG:3857 first among the candidates, and you can also click your area on the map to try the local UTM zone.

Converting in and out

  • KML, KMZ, GeoJSON and GPX output is converted to WGS 84 longitude and latitude.
  • SHP and CSV can stay in EPSG:3857, and this page presets it as their target. Point data in CSV then uses x and y columns, and lines and polygons use a wkt column.
  • To go the other way, the EPSG:4326 page presets longitude and latitude as the target.

Frequently asked questions

Is EPSG:3857 the same as EPSG:4326?
No. Both are based on WGS 84, but EPSG:4326 stores longitude and latitude in degrees, while EPSG:3857 stores projected x and y values in metres.
Why are my coordinates such large numbers?
EPSG:3857 measures metres from the point where the equator meets the prime meridian, so values in the millions are normal.
Can I keep EPSG:3857 in GeoJSON or KML?
No. Those formats are written in WGS 84 longitude and latitude. Download SHP or CSV to keep EPSG:3857 coordinates.