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Convert CH1903 to CH1903+

Convert coordinates from CH1903 (EPSG:4149) to CH1903+ (EPSG:4150) — 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-4150

Official EPSG transformation from CH1903 to CH1903+

The EPSG Geodetic Parameter Dataset defines 1 transformation between CH1903 (EPSG:4149) and CH1903+ (EPSG:4150). Its parameters, accuracy and area of use are listed below.

CH1903 to CH1903+ (1)

EPSG:15486±0.2 m
Method:
NTv2
Area of use:
Europe - Liechtenstein and Switzerland
Scope:
Approximation using NTv2 method of results of FINELTRA programme to an accuracy of 0.01m except at boundary of the Geneva and Vaud cantons, in city of Geneva and in the main valleys of Valais canton where differences are up to 20 cm.

Grid file: CHENyx06a.gsb

For improved accuracy (0.01m) use CHENyx06 interpolation programme FINELTRA. File CHENyx06 replaced by CHENyx06a; there is a small area at the border of the data where some more real data has been introduced. swisstopo consider the change insignificant.

Convert EPSG:4149 to EPSG:4150 in code

The same transformation with common GIS tools and libraries:

from pyproj import Transformer

transformer = Transformer.from_crs("EPSG:4149", "EPSG:4150", 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:4150 — 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:4150 →

Frequently asked questions

How accurate is converting CH1903 to CH1903+?
The most accurate official EPSG transformation between these systems is accurate to about ±0.2 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:4150 to EPSG:4149 →