  The most precise top quark mass measurements use kinematic reconstruction
methods, determining the top mass parameter of a Monte Carlo event generator,
$m_t^{\rm MC}$. Due to hadronization and parton shower dynamics, relating
$m_t^{\rm MC}$ to a field theory mass is difficult. We present a calibration
procedure to determine this relation using hadron level QCD predictions for
observables with kinematic mass sensitivity. Fitting $e^+e^-$ 2-Jettiness
calculations at NLL/NNLL order to Pythia 8.205, $m_t^{\rm MC}$ differs from the
pole mass by $900$/$600$ MeV, and agrees with the MSR mass within
uncertainties, $m_t^{\rm MC}\simeq m_{t,1\,{\rm GeV}}^{\rm MSR}$.
