  We present an initial-final mass relation derived from the
spectroscopically-complete volume-limited 40 pc sample of white dwarfs. The
relation is modelled using population synthesis methods to derive an initial
stellar population which can be fit to the observed mass distribution of white
dwarfs. The population synthesis accounts for binary evolution, where
higher-mass white dwarfs are more likely to be merger products than their
lower-mass counterparts. Uncertainties are accounted from the initial mass
function, stellar metallicity and age of the Galactic disc. We also consider
biases induced by the spectral type of the white dwarf where pure-hydrogen
atmosphere white dwarfs are likely to have more accurate masses, whilst the
full white dwarf sample will have fewer biases arising from spectral evolution.
We provide a four-piece segmented linear regression using Monte Carlo methods
to sample the 1-$\sigma$ range of uncertainty on the initial stellar
population. The derived initial-final mass relation provides a self-consistent
determination of the progenitor mass for white dwarfs in the Solar
neighbourhood which will be useful to study the local stellar formation
history.
