The large deformation crush behavior of axially loaded thin-walled circular columns was studied using an experimental approach. Many specimens were crushed by uniaxial quasi-static loads to establish a data base. The maximum load capacity, wavelength of buckled folds, mode shapes and post-mean buckling load magnitude were determined for many specimens. These values were then expressed in terms of cross-sectional geometry parameters, tube length, and material properties. Based on the results obtained, empirical design formulations were developed for predicting the crush characteristics, including mode of collapse, of circular columns.