Skip to content
transform

Convert KKJ to WGS 84

Convert coordinates from KKJ (EPSG:4123) to WGS 84 (EPSG:4326) — official EPSG transformation parameters, accuracy and area of use, with a free in-browser converter.

Direct link to this transformation: epsgtransform.com/transform/epsg-4123-to-epsg-4326

Official EPSG transformations from KKJ to WGS 84

The EPSG Geodetic Parameter Dataset defines 2 transformations between KKJ (EPSG:4123) and WGS 84 (EPSG:4326). Each applies to a specific area — pick the one whose area of use covers your data.

KKJ to WGS 84 (2)

EPSG:10099±1 mBest accuracy
Method:
Coordinate Frame rotation (geog2D domain)
Area of use:
Finland - onshore
Scope:
Transformation of coordinates at 1m to 2m level of accuracy.
ParameterValueUnit
X-axis translation(tx)-96.062metre
Y-axis translation(ty)-82.428metre
Z-axis translation(tz)-121.753metre
X-axis rotation(rx)-4.801arc-second
Y-axis rotation(ry)-0.345arc-second
Z-axis rotation(rz)1.376arc-second
Scale difference(ds)1.496parts per million

Parameter values from KKJ to ETRS89 (2) (code 10098). Assumes ETRS89 and WGS 84 can be considered the same to within the accuracy of the transformation. Replaces KKJ to WGS 84 (1) (code 1639).

KKJ to WGS 84 (1)

EPSG:1639±1.5 m
Method:
Position Vector transformation (geog2D domain)
Area of use:
Finland - onshore
Scope:
(null/copy) Approximation for medium and low accuracy applications assuming equality between plate-fixed static and earth-fixed dynamic CRSs, ignoring static/dynamic CRS differences.
ParameterValueUnit
X-axis translation(tx)-90.7metre
Y-axis translation(ty)-106.1metre
Z-axis translation(tz)-119.2metre
X-axis rotation(rx)4.09arc-second
Y-axis rotation(ry)0.218arc-second
Z-axis rotation(rz)-1.05arc-second
Scale difference(ds)1.37parts per million

Parameter values from KKJ to ETRS89 (1) (code 1638). Assumes ETRS89 and WGS 84 can be considered the same to within the accuracy of the transformation. Replaced by KKJ to WGS 84 (2) (code 10099).

Convert EPSG:4123 to EPSG:4326 in code

The same transformation with common GIS tools and libraries:

from pyproj import Transformer

transformer = Transformer.from_crs("EPSG:4123", "EPSG:4326", always_xy=True)
x, y = transformer.transform(-73.9857, 40.7484)
print(x, y)

Source: EPSG:4123 — KKJ

geographic system using latitude and longitude on an ellipsoid · Area of use: Finland - onshore

+proj=longlat +ellps=intl +towgs84=-96.062,-82.428,-121.753,4.801,0.345,-1.376,1.496 +no_defs +type=crs
More about EPSG:4123 →

Target: EPSG:4326 — WGS 84

geographic system using latitude and longitude on an ellipsoid · Area of use: World (by country)

+proj=longlat +datum=WGS84 +no_defs +type=crs
More about EPSG:4326 →

Frequently asked questions

How accurate is converting KKJ to WGS 84?
The most accurate official EPSG transformation between these systems is accurate to about ±1 m within its stated area of use. Browser-based converters approximate datum shifts with Helmert parameters; for surveying-grade work apply the official transformation in a desktop GIS.
Does my data leave the browser when I use this converter?
No. All coordinate transformations are computed locally in your browser using proj4js. The coordinates you enter are never transmitted to any server.
Need the reverse? Convert EPSG:4326 to EPSG:4123 →