We perform dimensional reductions of type IIA and type IIB double field theory in the flux formulation on Calabi-Yau three-folds and on K3 x T-2. In addition to geometric and non-geometric three-index fluxes and Ramond-Ramond fluxes, we include generalized dilaton fluxes. We relate our results to the scalar potentials of corresponding four-dimensional gauged supergravity theories, and we verify the expected behavior under mirror symmetry. For Calabi-Yau three-folds we extend this analysis to the full bosonic action including kinetic terms.