On-line coordinate transformation between coordinates (position and velocity) expressed in any ETRFxx realisations of the European Terrestrial Reference System (ETRS89) and any ITRFyy realizations of the International Terrestrial Reference System (ITRS).
In case output coordinates are requested at a different epoch then the provided input coordinates, it is mandatory to also input station velocities.

For transformations to and from the Galileo Terrestrial Reference Frame (GTRF), use ITRF. GTRF is aligned to current versions of the ITRF.

Explanation and examples are available from the following tutorial. However, note that with the introduction of the most recent transformation tool (August 2022), this tutorial has become slightly outdated.
If you use the ECTT tool, please cite doi:10.24414/ROB-EUREF-ECTT.

Change epoch format:

Transform to
Frame :
Epoch :
Updates of ECTT V2.0
  • 12 Apr. 2024: Added transformations from and to ETRF2020.
  • 14 Nov. 2022: Correction of last step of transformation from ETRFxx to ITRF2020. Thanks to Theo van Houten from Hydrographic Service of the Royal Netherlands Navy for notifying us of the problem.
  • 15 Sep. 2022: Print of epoch with two decimals instead of one.
  • 29 Aug. 2022: Release of V2.0 of ETRF/ITRF Coordinate Transformation Tool (ECTT) with reduced intermediate coordinate transformations. V2.0 includes now also transformations from and to ITRF2020.
Updates of ECTT V1.0