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Convert CH1903 to ETRS89

Convert coordinates from CH1903 (EPSG:4149) to ETRS89 (EPSG:4258) — 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-4258

Official EPSG transformations from CH1903 to ETRS89

The EPSG Geodetic Parameter Dataset defines 2 transformations between CH1903 (EPSG:4149) and ETRS89 (EPSG:4258). Each applies to a specific area — pick the one whose area of use covers your data.

CH1903 to ETRS89 (2)

EPSG:7674±0.25 mBest accuracy
Method:
NTv2
Area of use:
Europe - Liechtenstein and Switzerland
Scope:
Approximation (to better than 2cm) using NTv2 method of results of FINELTRA programme concatenated with LV-95 parameters.

Grid file: CHENyx06_ETRS.gsb

Equivalent to concatenation of CTs 15486 (CH1903 to CH1903+) and 1647 (CH1903+ to CHTRS95) to within 2cm. Also used as CT between CH1903 and CHTRS95 (see code 7673). Replaces CT code 1646. May be used as approximate CT CH1903 to WGS 84 - see code 7788.

CH1903 to ETRS89 (1)

EPSG:1646±1.5 m
Method:
Geocentric translations (geog2D domain)
Area of use:
Europe - Liechtenstein and Switzerland
Scope:
Parameter values from CH1903+ to ETRS89 (tfm code 1647) and are used as an approximation from CH1903 with a lesser accuracy of 1.5m which equates to the magnitude of distortions in the CH1903 network.
ParameterValueUnit
X-axis translation(tx)674.374metre
Y-axis translation(ty)15.056metre
Z-axis translation(tz)405.346metre

Parameter values from CH1903+ to ETRS89 (tfm code 1647). In EPSG db v5.2 to v8.9 given to 1dm; the difference in output of cms is considered by swisstopo to be insignificant given the tfm accuracy. Superseded by CH1903 to ETRS89 (2) (tfm code 7674).

Convert EPSG:4149 to EPSG:4258 in code

The same transformation with common GIS tools and libraries:

from pyproj import Transformer

transformer = Transformer.from_crs("EPSG:4149", "EPSG:4258", 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:4258 — ETRS89

geographic system using latitude and longitude on an ellipsoid · Area of use: Europe - ETRF by country

+proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs +type=crs
More about EPSG:4258 →

Frequently asked questions

How accurate is converting CH1903 to ETRS89?
The most accurate official EPSG transformation between these systems is accurate to about ±0.25 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:4258 to EPSG:4149 →