Correlative models derived from empirical relations describing synthesis-structure relationships are essential to guiding and improving future research and development of functional materials, yet few models exist for the prediction of structural distortions in perovskites. In this work, a data-mining approach has been employed to collect structural data for trigonally distorted perovskites in specific model systems. Correlative models were developed which describe the relationship between thec/aratio and the ratio of the pseudocubic lattice constant (a(pc)) to the B-X bond length (r(BX)). General models were then created for thec/aratio in terms of the modified tolerance factor for trigonal perovskites withR3 over bar csymmetry and perovskite-like compounds withR3csymmetry. These models accurately predict the lattice constants in trigonally distorted perovskites and LiNbO(3)type perovskite-like compounds. In addition, a general model was developed, which accurately predicts polarization in trigonal LiNbO(3)type perovskite-like compounds in space groupR3c.