Latitude/Longitude to Web Mercator converter
On a web map, Greenland looks as big as Africa. That is Web Mercator. This converter gives you EPSG:3857 X and Y in meters, the exact numbers Google Maps, OpenStreetMap, Leaflet and Mapbox tiles use internally. Free and in your browser.
Bulk convert a list of coordinates
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.
About this conversion
Web Mercator (EPSG:3857) expresses positions as meters 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.
How to use it
- Enter your latitude and longitude above (any of decimal degrees, DMS or DDM, auto-detected).
- Read the highlighted result and click Copy. Every other format is shown too.
- Nothing is uploaded, it all runs in your browser.
How latitude and longitude to web mercator works
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 meters 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 meters, 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.
Worked examples
Projecting a familiar point
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 meters; the Y grows non-linearly with latitude, which is why the projection stretches toward the poles.
The equator and the sign
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.
The latitude limit
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.
Precision and rounding
Web Mercator coordinates are large meter values, commonly quoted to a couple of decimal places, but do not read distances straight off them near the poles: a meter of Web Mercator Y is not a meter on the ground except at the equator. For visualization this does not matter; for measurement, reproject to an equal-area or UTM system first.
Quick reference
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 | 16,832,542, -4,010,880 |
Accepted input formats
Enter WGS84 latitude and longitude in decimal degrees or DMS. The result is EPSG:3857 X/Y in meters, 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.
Where you will use it
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 meters; to read them as latitude and longitude, use the meters to decimal degrees converter and pick Web Mercator as the source.
What to do next
Web Mercator meters 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 meter grid instead, use latitude/longitude to UTM.
Common mistakes to avoid
- Measuring area or distance in Web Mercator. It distorts badly away from the equator; use UTM or an equal-area projection for measurements.
- Confusing 3857 with 4326. One is meters, the other degrees. Passing degrees where meters are expected puts data near the origin.
- Going past ±85° latitude. Web Mercator cannot represent the poles; clip or choose a polar projection instead.
Frequently asked questions
Is Web Mercator the same as WGS84?
No. WGS84 (EPSG:4326) is longitude/latitude in degrees; Web Mercator (EPSG:3857) is a projection of it into meters. They describe the same place with very different numbers.
Why do web maps use Web Mercator?
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.
Does Web Mercator distort areas?
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.
Are my coordinates sent anywhere?
No. Every conversion is computed in your browser with plain math, so nothing is uploaded and the tool keeps working offline once loaded.