The systems and methods of the present disclosure calibrate impedance loss model parameters associated with an electrosurgical system having no external cabling or having external cabling with a fixed or known reactance, and obtain accurate electrical measurements of a tissue site by compensating for impedance losses associated with the transmission line of an electrosurgical device using the calibrated impedance loss model parameters. A computer system stores voltage and current sensor data for a range of different test loads and calculates sensed impedance values for each test load. The computer system then predicts a phase value for each load using each respective load impedance value. The computer system back calculates impedance loss model parameters including a source impedance parameter and a leakage impedance parameter based upon the voltage and current sensor data, the predicted phase values, and the impedance values of the test loads. During operation, the electrosurgical device senses a voltage and a current, predicts a phase value based upon the sensed voltage and current, and calculates metrics at the tissue site based upon the sensed voltage and current, the predicted phase value, the source impedance parameter, and the leakage impedance parameter.
