  Exoplanets form in protoplanetary accretion discs. The total protoplanetary
disc mass is the most fundamental parameter, since it sets the mass budget for
planet formation. Although observations with the Atacama Large
Millimeter/Submillimeter array (ALMA) have dramatically increased our
understanding of these discs, total protoplanetary disc mass remains difficult
to measure. If a disc is sufficiency massive ($\gtrsim$ 10\% of the host star
mass), it can excite gravitational instability (GI). Recently, it has been
revealed that GI leaves kinematic imprints of its presence known as the "GI
Wiggle." In this work, we use numerical simulations to empirically determine an
approximately linear relationship between the amplitude of the wiggle and the
host disc-to-star mass ratio, and show that measurements of the amplitude are
possible with the spatial and spectral capabilities of ALMA. These measurements
can therefore be used to constrain disc-to-star mass ratio.
