The Coordinate Transformation function allows you to transform coordinates from one coordinate system to another. You can enter coordinates as text, import them from a file, select locations on a map, or import them from the clipboard.
Coordinate transformation entails the following steps, which are described in more detail below:
- Select the coordinate and height systems
- Enter original coordinates
- Perform the transfomration and save the result to a file
- Other functions
Go to the Paikkatietoikkuna geodata portal.
Return to the front page of the Paikkatietoikkuna user guide.
Select the coordinate and vertical reference systems
Coordinate reference system
Before entering the coordinates, you must define the original coordinate system – that is, the coordinate system in which the coordinates are originally defined – and the result coordinate system to which you want to transform them.
The national projected coordinate system in Finland is ETRS-TM35FIN. It is used also in the Finnish Geoportal.
The commonly used WGS84 coordinate system is not available in this service. Instead, select the EUREF-FIN-G80 coordinate system. The deviation in coordinate values between these systems is less than one metre.
Learn more about coordinate systems (only in Finnish and Swedish).
Vertical coordinate system
If you want to transform heights as well, choose the vertical coordinate system for the original and result coordinates. The options are N2000, N60 and N43.
In Finland, the national height system is N2000. The N2000 system used by the service has been updated to the new geoid model published in 2024.
Read more about the new geoid model.
Please note that the N43 height system does not cover the whole of Northern Finland.
Additional Options
You can also specify more precise parameters for the coordinate transformation. Click Show all coordinate system selections to filter the number of selectable coordinate systems.
- Geodetic datum: Choose whether the coordinates are defined in the KKJ, EUREF-FIN or ETRS89 datum. A datum is a set of parameters used to determine the origin, scale and orientation of a coordinate system in relation to the surface of the Earth.
- Coordinate system: Choose whether the coordinates are indicated in a rectangular or geographical coordinate system and in 2D or 3D (height included). If you select “Rectangular 2D (Plane)” as the coordinate system, you can filter the options by selecting the map projection system.
Enter original coordinates
Enter the original coordinates in one of the following ways:
- Enter the coordinates in the table.
- Import coordinates from a text file.
- Select the locations of points on the map.
- Copy coordinates from the clipboard.
Enter the coordinates into the table
Enter the coordinates directly into the Original coordinates table. Column headings are determined by the selected coordinate system.
If you accidentally entered the coordinates backwards, for example, entering the east coordinates in the north coordinate column, you can reverse them by clicking the Reverse coordinates button in the upper right corner of the column.
Import coordinates from a text file
If you have the coordinates saved to a file, you can enter them into the service by uploading that file. The service supports text files with the file extension .txt, .text or .csv.
Click the Import from file button to select a file from your computer and check the file settings:
- File: Drag a file to the rectangular area at the top of the window that opens, or click on the rectangle to select the file using the file browser. The service will automatically fill in the other information based on the selected file.
- Coordinate reference system: Select the coordinate system in which the coordinates are recorded in the file. This selection is also updated in the main Coordinate Transformation window.
- Vertical reference system: Select the vertical reference system in which the heights and depths are recorded in the file. This selection is also updated in the main Coordinate Transformation window.
- Number of header rows: Select how many rows in the file are above the coordinate rows.
- Column separator: Select which delimiter separates the columns in the file. The options are tab, space, comma, semicolon and vertical bar.
- Decimal separator: Select whether to use a period or a comma as a decimal separator. Please note that the column separator and the decimal separator cannot be the same character.
- Angle format / unit: Select the unit and format where the angle values of the coordinates are in the file. This option only appears if the coordinates are indicated as angles in the coordinate system you selected. The unit of angle can be degrees, gon, or radians. In addition, coordinates can be expressed in degrees, seconds and minutes.
- Coordinates include identifiers: Select this if a point identifier is defined at the beginning of the line before the coordinates. The identifier and coordinates are separated by the column separator specified above. The identifier can contain both alphabetical and numerical characters. If no identifiers are specified, they are automatically generated, starting with 1.
Press Done, and the coordinate data from the file will be displayed in the Original coordinates table.
Select locations on the map
Click Select locations on the map, then click on the desired points on the map. Click Done, and the coordinates of the points you clicked will appear in the Original coordinates table. When selecting coordinates from the map, they are always in the ETRS-TM35FIN coordinate system.
You can change the points in the table by clicking Select locations on the map again. In the window that opens, select whether you want to add or delete points. To remove points select Delete points and click the point you want to delete.
Import coordinates from the clipboard
Click Import from clipboard and paste the coordinates into the window that opens. Separate the coordinates with a semicolon or a tab.
Finally, press Import. The coordinates are displayed in the Original coordinates table.
Perform the transformation and save the result to a file
Click Transform, and the transformed coordinates will appear in the table on the right. The table is a preview of the transformed data.
After transformation, you can save the data to a file by clicking Save to file. In the window that opens, check the file settings and, if necessary, correct:
- File name: Give the file a name of your choice. If you do not provide a file extension, the service will automatically save the coordinates to a .txt file. To save coordinates in CSV format, add the extension .csv to the file name.
- Column separator: Select which delimiter separates the columns in the file. The options are tab, space, comma, semicolon and vertical bar.
- Decimal separator: Select whether to use a period or a comma as a decimal separator. Please note that the column separator and the decimal separator cannot be the same character.
- Decimal precision: Select the desired decimal place precision for the coordinates. By default, coordinates are displayed with a resolution of 1 mm.
- Line separator: Select the operating system you are using. Line breaks in the file are marked with a line separator according to the selected operating system.
- Add information about the used coordinate and height reference systems into the beginning of the file: Select this option if you want the EPSG code, name and coordinate and height units of the coordinate and height reference systems to be added in the beginning of the file.
- Create identifiers for coordinate rows: Select this option if you want to add an identifier to each row. The identifier is a sequential number, with the first one being 1. One row corresponds to one point.
- Reverse coordinates: Select this option if you want to record the coordinates in the file in the reverse order to that in which they appear in the Result coordinates table. For example, if the X-coordinate in the table comes before the Y-coordinate, the Y-coordinate is written in the file before the X-coordinate.
- Add cardinals (N, E, W, S): Add a cardinal direction letter (N = North, E = East, W = West, S = South) to the coordinate values. If a coordinate is negative, the opposite cardinal direction letter will be added in front of it. East is the opposite direction of west, and north is the opposite direction of south.
Finally, press Save to file to save the file containing the coordinates to your browser’s downloaded files.
Other functions
Show locations on the map
Click Show locations on the map to see the locations of the points in the table on a map using the ETRS-TM35FIN coordinate system. For each point, the east and north coordinates (E, N) are displayed.
Reset
Click Reset to reset the whole form. The function clears all selections and the coordinate table.