RD Coordinate Converter
Convert Rijksdriehoek (EPSG:28992) to WGS84 latitude and longitude, and back again. Everything happens in your browser, accurate to about 30 centimetres inside the Netherlands.
Type in either panel. The other side updates as you go.
RD (Rijksdriehoek)
WGS84 (latitude, longitude)
Degrees, minutes, seconds
Why the Netherlands has its own coordinate system
The earth is a sphere and a map is flat. Every projection therefore has to pick what it distorts: area, angle or distance. Rijksdriehoek is a stereographic projection tuned specifically to the Netherlands, so shapes and angles within the country stay almost undistorted. That makes it well suited to cadastral maps, zoning plans and civil engineering.
The system takes its name from the triangulation survey that established it in the nineteenth century. Its origin is the Onze Lieve Vrouwetoren in Amersfoort. To avoid negative numbers that point was given the values X 155000 and Y 463000 rather than 0 and 0. As a result every Dutch location has positive coordinates, and X values are always smaller than Y values, which makes a swapped pair easy to spot.
Where you run into RD coordinates
Almost all Dutch government data uses RD. The address and buildings register (BAG), the Kadaster, the large-scale topography register (BGT), the national height model (AHN) and most municipal GIS systems all publish coordinates in this system. The moment you want to combine that data with anything that speaks WGS84, such as a GPS receiver, a web map or the EXIF data in a photo, you have to convert.
The reverse is just as common. A location from a phone, or from the EXIF data in a photo, arrives as WGS84 and has to become RD before it can be placed in a municipal mapping system.
Common mistakes
The most frequent error is swapping X and Y. Inside the Netherlands X runs roughly from 0 to 300000 and Y from 300000 to 630000, so an X value above 300000 is certainly wrong. The second classic is WGS84 ordering: nearly every web map wants latitude first and longitude second, but GeoJSON and many GIS libraries put longitude first.
Finally, watch the decimal separator. Dutch software often exports with a comma while most mapping services expect a point. This tool accepts either.
From coordinate to photo, and back
A coordinate tells you where something is, but not what is there. Working the other way round, from a photo with no location, converting does not help. In that case GeoPin works the location out from the image itself, comparing the photo against an index of Dutch street-level imagery, and returns the result as WGS84 coordinates with an address and postcode.
Frequently asked questions
What exactly is the RD system?
Rijksdriehoek is the official Dutch coordinate system, formally EPSG:28992. It is a flat projection whose origin sits at the Onze Lieve Vrouwetoren in Amersfoort, which was assigned the coordinates X 155000 and Y 463000. That artificial offset means every location in the Netherlands gets positive X and Y values, which makes the numbers easier to work with.
How accurate is this conversion?
The approximation formulas used here stay within roughly 30 centimetres of the full RDNAPTRANS datum transformation anywhere in the Netherlands. For mapping, GIS work, address lookup and virtually every practical use that is more than enough. For cadastral survey or NAP height work you should use RDNAPTRANS itself.
Why does the conversion only work in the Netherlands?
The formulas are polynomials fitted to the Dutch area. Outside those bounds the error climbs quickly into tens of metres or worse. The tool therefore warns as soon as you enter a point that falls outside the Netherlands.
Is X the east-west axis or the north-south one?
X is east-west and Y is north-south. That is the opposite order to how WGS84 is usually written, where latitude (north-south) comes first. Swapping X and Y is a common mistake and puts the point somewhere in the North Sea or outside the grid entirely.
Are my coordinates sent anywhere?
No. The whole calculation runs in JavaScript in your own browser. No request goes to a server at all, so the tool keeps working offline once the page has loaded.