Convert RT90 to WGS 84

Convert coordinates from RT90 (EPSG:4124) to WGS 84 (EPSG:4326) — official EPSG transformation parameters, accuracy and area of use, with a free in-browser converter.

From

Input (lon, lat (decimal degrees))

Output (lon, lat (decimal degrees))

Direct link to this transformation: epsgtransform.com/transform/epsg-4124-to-epsg-4326

Official EPSG transformations from RT90 to WGS 84

The EPSG Geodetic Parameter Dataset defines 2 transformations between RT90 (EPSG:4124) and WGS 84 (EPSG:4326). Each applies to a specific area — pick the one whose area of use covers your data.

RT90 to WGS 84 (1)

EPSG:1680±1 mBest accuracy

Method:: Coordinate Frame rotation (geog2D domain)
Area of use:: Sweden
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.

Parameter	Value	Unit
X-axis translation(tx)	419.3836	metre
Y-axis translation(ty)	99.3335	metre
Z-axis translation(tz)	591.3451	metre
X-axis rotation(rx)	-0.850389	arc-second
Y-axis rotation(ry)	-1.817277	arc-second
Z-axis rotation(rz)	7.862238	arc-second
Scale difference(ds)	-0.99496	parts per million

Parameter values from RT90 to ETRS89 (1) (code 1437) assuming that ETRS89 is equivalent to WGS 84 within the accuracy of the transformation. Replaced by RT90 to WGS 84 (2) (code 1896) from 2001.

RT90 to WGS 84 (2)

EPSG:1896±1 m

Method:: Coordinate Frame rotation (geog2D domain)
Area of use:: Sweden
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.

Parameter	Value	Unit
X-axis translation(tx)	414.1	metre
Y-axis translation(ty)	41.3	metre
Z-axis translation(tz)	603.1	metre
X-axis rotation(rx)	0.855	arc-second
Y-axis rotation(ry)	-2.141	arc-second
Z-axis rotation(rz)	7.023	arc-second
Scale difference(ds)	0	parts per million

Parameter values from RT90 to SWEREF99 (1) (code 1895) assuming that SWEREF99 is equivalent to WGS 84 within the accuracy of the transformation. Replaces RT90 to WGS 84 (1) (code 1680).

Convert EPSG:4124 to EPSG:4326 in code

The same transformation with common GIS tools and libraries:

from pyproj import Transformer

transformer = Transformer.from_crs("EPSG:4124", "EPSG:4326", always_xy=True)
x, y = transformer.transform(-73.9857, 40.7484)
print(x, y)

Source: EPSG:4124 — RT90

geographic system using latitude and longitude on an ellipsoid · Area of use: Sweden

+proj=longlat +ellps=bessel +towgs84=414.1,41.3,603.1,-0.855,2.141,-7.023,0 +no_defs +type=crs

More about EPSG:4124 →

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 RT90 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:4124 →