  There are several methods to calculate the radiative and kinetic power of
relativistic jets, but their results can differ by one or two orders of
magnitude. Therefore, it is necessary to perform a calibration of the jet
power, to understand the reasons for these differences (whether wrong
hypotheses or intrinsic source variability), and if it is possible to converge
to a reliable measurement of this physical quantity. We present preliminary
results of a project aimed at calibrating the power of relativistic jets in
active galactic nuclei (AGN) and X-ray binaries (XRB). We started by selecting
all the AGN associations with known redshift in the Fourth Fermi LAT Gamma-Ray
Catalog (4FGL). We then calculated the radiative and/or kinetic powers from
available data or we extracted this information from literature. We compare the
values obtained for overlapping samples and highlight early conclusions.
