A generalized hard x-ray detection model for microchannel plate (MCP) detectors has been developed. This model includes all geometrical and compositional parameters of an MCP and the energy of a detected x-ray. An analytical investigation and numerical calculation of the detection efficiency were carried out; data obtained were compared with experimental results. A square and hexagonal channel MCP were considered in addition to a traditional circular channel MCP. Moreover, it is shown that the first ones have advantages as x-ray detectors. ©1997 American Institute of Physics.