Unit for calculating torque in refrigeration cycle and control unit using the same

A unit for calculating a compressor torque in a refrigeration cycle having a variable displacement compressor, a condenser, a pressure reducing mechanism and an evaporator, wherein the compressor torque is calculated from a pressure difference between a refrigerant discharge pressure and a refrigerant suction pressure of the compressor or a physical value having a correlation with the pressure difference, and a control unit using the same. The compressor torque may be adequately estimated without using a flow sensor.