  More than 80 giant planets are known by mass and radius. Their interior
structure in terms of core mass, number of layers, and composition however is
still poorly known. An overview is presented about the core mass Mcore and
envelope mass of metals MZ in Jupiter as predicted by various equations of
state. It is argued that the uncertainty about the true H/He EOS in a pressure
regime where the gravitational moments J2 and J4 are most sensitive, i.e.
between 0.5 and 4 Mbar, is in part responsible for the broad range Mcore=0-18
Mearth, MZ=0-38 Mearth, and Mcore+MZ=14-38 Mearth currently offered for
Jupiter. We then compare the Jupiter models obtained when we only match J2 with
the range of solutions for the exoplanet GJ436b, when we match an assumed tidal
Love number k2 value.
