Convert ITRF91 to ETRF91

Convert coordinates from ITRF91 (EPSG:4913) to ETRF91 (EPSG:7918) — official EPSG transformation parameters, accuracy and area of use, with a free in-browser converter.

From

Input (x, y)

Output (x, y)

Direct link to this transformation: epsgtransform.com/transform/epsg-4913-to-epsg-7918

Official EPSG transformation from ITRF91 to ETRF91

The EPSG Geodetic Parameter Dataset defines 1 transformation between ITRF91 (EPSG:4913) and ETRF91 (EPSG:7918). Its parameters, accuracy and area of use are listed below.

ITRF91 to ETRF91 (1)

EPSG:7934±0 m

Method:: Time-dependent Position Vector tfm (geocentric)
Area of use:: Europe - ETRF
Scope:: Geodesy. Defines ETRF91.

Parameter	Value	Unit
X-axis translation(tx)	2.1	centimetre
Y-axis translation(ty)	2.5	centimetre
Z-axis translation(tz)	-3.7	centimetre
X-axis rotation(rx)	0	milliarc-second
Y-axis rotation(ry)	0	milliarc-second
Z-axis rotation(rz)	0	milliarc-second
Scale difference(ds)	0	parts per billion
rate tx	0	centimetres per year
rate ty	0	centimetres per year
rate tz	0	centimetres per year
rate rx	0.21	milliarc-seconds per year
rate ry	0.52	milliarc-seconds per year
rate rz	-0.68	milliarc-seconds per year
rate ds	0	parts per billion per year
epoch	1989	year

Scale difference in ppb and scale difference rate in ppb/yr where 1/billion = 1E-9 or nm/m.

Convert EPSG:4913 to EPSG:7918 in code

The same transformation with common GIS tools and libraries:

from pyproj import Transformer

transformer = Transformer.from_crs("EPSG:4913", "EPSG:7918", always_xy=True)
x, y = transformer.transform(-73.9857, 40.7484)
print(x, y)

Source: EPSG:4913 — ITRF91

geocentric Cartesian system (Earth-centred Earth-fixed) · Area of use: World

+proj=geocent +ellps=GRS80 +units=m +no_defs +type=crs

More about EPSG:4913 →

Target: EPSG:7918 — ETRF91

geocentric Cartesian system (Earth-centred Earth-fixed) · Area of use: Europe - ETRF

+proj=geocent +ellps=GRS80 +units=m +no_defs +type=crs

More about EPSG:7918 →

Frequently asked questions

How accurate is converting ITRF91 to ETRF91?: The most accurate official EPSG transformation between these systems is accurate to about ±0 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:7918 to EPSG:4913 →