  We calculate numerically the entanglement entropy of free fermion ground
states in one-, two- and three-dimensional Anderson models, and find that it
obeys the area law as long as the linear size of the subsystem is sufficiently
larger than the mean free path. This result holds in the metallic phase of the
three-dimensional Anderson model, where the mean free path is finite although
the localization length is infinite. Relation between the present results and
earlier ones on area law violation in special one-dimensional models that
support metallic phases is discussed.
