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Convert CH1903 to WGS 84

Convert coordinates from CH1903 (EPSG:4149) 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-4149-to-epsg-4326

Official EPSG transformations from CH1903 to WGS 84

The EPSG Geodetic Parameter Dataset defines 3 transformations between CH1903 (EPSG:4149) and WGS 84 (EPSG:4326). Each applies to a specific area — pick the one whose area of use covers your data.

CH1903 to WGS 84 (1)

EPSG:1753±1 mBest accuracy
Method:
Coordinate Frame rotation (geog2D domain)
Area of use:
Europe - Liechtenstein and Switzerland
Scope:
GRANIT coordinate transformation programme between 1987 and 1997.
ParameterValueUnit
X-axis translation(tx)660.077metre
Y-axis translation(ty)13.551metre
Z-axis translation(tz)369.344metre
X-axis rotation(rx)2.484centesimal second
Y-axis rotation(ry)1.783centesimal second
Z-axis rotation(rz)2.939centesimal second
Scale difference(ds)5.66parts per million

Implemented in Bundesamt für Landestopografie programme GRANIT. Used from 1987 to 1997. Not recommended for current usage - replaced by CH1903 to WGS 84 (2) (code 1766).

CH1903 to WGS 84 (2)

EPSG:1766±1.5 m
Method:
Geocentric translations (geog2D domain)
Area of use:
Europe - Liechtenstein and Switzerland
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)674.374metre
Y-axis translation(ty)15.056metre
Z-axis translation(tz)405.346metre

Parameters values from CH1903 to ETRS89 (1) (tfm code 1646) assuming ETRS89 and WGS 84 can be considered the same to within the accuracy of the transformation. Replaces CH1903 to WGS 84 (1) (code 1753). Replaced by CH1903 to WGS 84 (3) (code 7788).

CH1903 to WGS 84 (3)

EPSG:7788±1.5 m
Method:
NTv2
Area of use:
Europe - Liechtenstein and Switzerland
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.

Grid file: CHENyx06_ETRS.gsb

Parameter values from CH1903 to ETRS89 (2) (code 7674) assuming that ETRS89 is equivalent to WGS 84 within the accuracy of the transformation. Equivalent to concatenation of transformations 15486 and 1676.

Convert EPSG:4149 to EPSG:4326 in code

The same transformation with common GIS tools and libraries:

from pyproj import Transformer

transformer = Transformer.from_crs("EPSG:4149", "EPSG:4326", always_xy=True)
x, y = transformer.transform(-73.9857, 40.7484)
print(x, y)

Source: EPSG:4149 — CH1903

geographic system using latitude and longitude on an ellipsoid · Area of use: Europe - Liechtenstein and Switzerland

+proj=longlat +ellps=bessel +towgs84=674.374,15.056,405.346,0,0,0,0 +no_defs +type=crs
More about EPSG:4149 →

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 CH1903 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 (including the grid-shift files listed below) 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:4149 →