  We analyze 4\,050 wide binary star systems involving a white dwarf (WD) and
usually a main sequence (MS) star, drawn from the large sample assembled by
\citet[][hereafter, T20]{Tian_2020}. Using the modeling code BASE-9, we
determine the system's ages, the WD progenitors' ZAMS masses, the extinction
values ($A_V$), and the distance moduli. Discarding the cases with poor age
convergences, we obtain ages for 3\,551 WDs, with a median age precision of
$\sigma_{\tau}/\tau = 20$\%, and system ages typically in the range of 1-6 Gyr.
We validated these ages against the very few known clusters and through
cross-validation of 236 WD-WD binaries. Under the assumption that the
components are co-eval in a binary system, this provides precise age
constraints on the usually low-mass MS companions, mostly inaccessible by any
other means.
