  We summarize and combine direct measurements of the mass of the $W$ boson in
$\sqrt{s} = 1.96 \text{TeV}$ proton-antiproton collision data collected by CDF
and D0 experiments at the Fermilab Tevatron Collider. Earlier measurements from
CDF and D0 are combined with the two latest, more precise measurements: a CDF
measurement in the electron and muon channels using data corresponding to $2.2
\mathrm{fb}^{-1}$ of integrated luminosity, and a D0 measurement in the
electron channel using data corresponding to $4.3 \mathrm{fb}^{-1}$ of
integrated luminosity. The resulting Tevatron average for the mass of the $W$
boson is $\MW = 80\,387 \pm 16 \text{MeV}$. Including measurements obtained in
electron-positron collisions at LEP yields the most precise value of $\MW =
80\,385 \pm 15 \text{MeV}$.
