tidalspin uses a Bayesian approach to infer posterior distributions of a black hole's parameters (mass and spin) in an observed tidal disruption event, given a prior estimate of the black hole’s mass (e.g., from a galactic scaling relationship, or the tidal disruption event’s observed properties). These posterior distributions will only utilize the properties of tidal forces in their inference. tidalspin can be applied to the population of tidal disruption events already discovered.