Convert latitude/longitude (WGS84) to Web Mercator (EPSG:3857) X/Y in metres, the projection Google Maps, OpenStreetMap and most web maps draw in. Free and in your browser.
Paste one coordinate per line as lat, lon (decimal, DMS or DDM all work), then convert them all at once and download the results as CSV.
Web Mercator (EPSG:3857) expresses positions as metres east/north of the origin, and is what nearly every web basemap uses internally. Converting lat/long to 3857 is handy when a mapping API or tile scheme wants projected X/Y.
Web Mercator (EPSG:3857) is the projection every slippy web map uses, Google Maps, OpenStreetMap, Mapbox and Leaflet tiles. It projects latitude and longitude onto a square in metres so that tiles line up at every zoom level. Longitude scales linearly, but latitude does not: the y value stretches more and more toward the poles, which is why Greenland looks as big as Africa on a web map.
The output is an X and a Y in metres, spanning roughly ±20,037,508 m. Web Mercator treats the Earth as a sphere for speed, so it is perfect for display but not for precise distance or area measurement, use UTM or a local projection for that.
For 51.5074, -0.1278 (London), Web Mercator gives about -14,226 m easting (X), 6,711,544 m northing (Y). The X comes straight from longitude scaled to metres; the Y grows non-linearly with latitude, which is why the projection stretches toward the poles.
At the equator (latitude 0) the Web Mercator Y is 0, and it rises as you go north and falls (negative) as you go south. Longitude 0 gives X = 0. So 0, 0 maps to 0, 0, and a point in the southern, western hemisphere has both X and Y negative.
Web Mercator is only defined to about ±85.06° latitude, because the maths runs to infinity at the poles. Coordinates beyond that cannot be drawn on a standard web map and are clipped.
Web Mercator coordinates are large metre values, commonly quoted to a couple of decimal places, but do not read distances straight off them near the poles: a metre of Web Mercator Y is not a metre on the ground except at the equator. For visualisation this does not matter; for measurement, reproject to an equal-area or UTM system first.
A few well-known places, converted, so you can sanity-check your own numbers against them.
| Place | Lat/Long | Web Mercator (X, Y m) |
|---|---|---|
| London | 51.5074, -0.1278 | -14,226, 6,711,544 |
| New York | 40.7128, -74.0060 | -8,238,310, 4,970,072 |
| Equator/Greenwich | 0, 0 | 0, 0 |
| Sydney | -33.8688, 151.2093 | 16,832,610, -4,010,880 |
Enter WGS84 latitude and longitude in decimal degrees or DMS. The result is EPSG:3857 X/Y in metres, the exact numbers a Leaflet, Mapbox or OpenLayers map uses internally, so you can hand them straight to a tile scheme or a mapping API.
You do not have to reformat anything first. The box detects the notation from what you paste, so every one of these is understood:
| You can type | The tool reads it as | Notation |
|---|---|---|
48.8584 | 48.8584 | Decimal degrees |
-33.8688 | -33.8688 (south) | Decimal degrees, signed |
48°51'30"N | 48.85833 | DMS with symbols |
48 51 30 N | 48.85833 | DMS with spaces |
48:51:30N | 48.85833 | DMS with colons |
N48.8584 | 48.8584 | Hemisphere letter first |
48°51.5'N | 48.85833 | Degrees decimal minutes |
The hemisphere is taken from an N, S, E or W letter anywhere in the value, or from a leading minus sign. If both are missing, a positive number is assumed north or east.
You convert latitude and longitude to Web Mercator whenever you feed data into a web-map tile pipeline or a tool that expects EPSG:3857. Conversely, coordinates copied out of a web map are often already in Web Mercator metres; to read them as latitude and longitude, use the meters to decimal degrees converter and pick Web Mercator as the source.
Web Mercator metres feed straight into web-map tile pipelines. To turn Web Mercator X/Y back into latitude and longitude, use the meters to decimal degrees converter with Web Mercator selected. For the surveyor's metre grid instead, use latitude/longitude to UTM.
No. WGS84 (EPSG:4326) is longitude/latitude in degrees; Web Mercator (EPSG:3857) is a projection of it into metres. They describe the same place with very different numbers.
Web Mercator maps the round Earth onto a simple square tile grid, which makes tiled basemaps fast to serve. Google Maps, OpenStreetMap and Mapbox all draw in it.
Yes. It stretches areas badly toward the poles, so Greenland looks huge. It is fine for navigation and display, but do not measure area in it. Use UTM or an equal-area projection instead.
No. Every conversion is computed in your browser with plain math, so nothing is uploaded and the tool keeps working offline once loaded.
