The present invention provides systems and methods for calibrating a transceiver. In an exemplary embodiment, a method of operating a modular wide-range microwave transceiver, each having precalibrated modules, comprises the steps of coupling the precalibrated modules to form a radio unit, each module having a module memory storing predetermined calibration values, coupling the radio unit to a signal processing unit, determining a first attenuation value by adjusting a first transmit attenuator to achieve a predetermined target output of a AGC detector, and storing the first attenuation value in a first module memory, and when an RF loopback switch is coupled as part of the radio unit, determining a received signal level (RSL) correction factor and transmit output power correction factor based on a loop-back switch insertion loss.