  We derive a determinant expression for overlaps of Bethe states of the XXZ
spin chain with the N{\'e}el state, the ground state of the system in the
antiferromagnetic Ising limit. Our formula, of determinant form, is valid for
generic system size. Interestingly, it is remarkably similar to the well-known
Gaudin formula for the norm of Bethe states, and to another recently-derived
overlap formula appearing in the Lieb-Liniger model.
