Determining accurate velocity measurements from observations of the Sun is of vital importance to solar physicists who are studying the wave dynamics in the solar atmosphere. Weak chromospheric absorption lines, due to dynamic events in the solar atmosphere, often consist of multiple spectral components. Isolating these components allows for the velocity field of the dynamic and quiescent regimes to be studied independently. However, isolating such components is particularly challenging due to the wide variety of spectral shapes present in the same dataset. MCALF provides a novel method and infrastructure to determine Doppler velocities in a large dataset. Each spectrum is fitted with a model adapted to its specific spectral shape.