  The formal degree conjecture relates the formal degree of an irreducible
square-integrable representation of a reductive group over a local field to the
special value of the adjoint $\gamma$-factor of its $L$-parameter. In this
paper, we prove the formal degree conjecture for odd special orthogonal and
metaplectic groups in the generic case, which combined with Arthur's work on
the local Langlands correspondence implies the conjecture in full generality.
