  The formation history of giant planets determines their primordial structure
and consequent evolution. We simulate various formation paths of Jupiter to
determine its primordial entropy, and find that a common outcome is for
proto-Jupiter to have non-convective regions in its interior. We use planet
formation models to calculate how the entropy and post-formation luminosity
depend on model properties such as the solid accretion rate and opacity, and
show that the gas accretion rate and its time evolution play a key role in
determining the entropy profile. The predicted luminosity of Jupiter shortly
after formation varies by a factor of $2$--$3$ for different choices of model
parameters. We find that entropy gradients inside Jupiter persist for $\sim 10\
{\rm Myr}$ after formation. We suggest that these gradients should be
considered together with heavy-element composition gradients when modeling
Jupiter's evolution and internal structure.
