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Convert CH1903 to CHTRS95

Convert coordinates from CH1903 (EPSG:4149) to CHTRS95 (EPSG:4151) — 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-4151

Official EPSG transformation from CH1903 to CHTRS95

The EPSG Geodetic Parameter Dataset defines 1 transformation between CH1903 (EPSG:4149) and CHTRS95 (EPSG:4151). Its parameters, accuracy and area of use are listed below.

CH1903 to CHTRS95 (1)

EPSG:7673±0.25 m
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 transformations 15486 (CH1903 to CH1903+) and 1509 (CH1903+ to CHTRS95) to within 2cm. Also used as transformation between CH1903 and ETRS89 (see code 7674).

Convert EPSG:4149 to EPSG:4151 in code

The same transformation with common GIS tools and libraries:

from pyproj import Transformer

transformer = Transformer.from_crs("EPSG:4149", "EPSG:4151", 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:4151 — CHTRS95

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

+proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs +type=crs
More about EPSG:4151 →

Frequently asked questions

How accurate is converting CH1903 to CHTRS95?
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:4151 to EPSG:4149 →