A hemodynamic monitor implements an adaptive method that optimally estimates scaling and offset calibration parameters by using a computationally efficient, iterative online method to minimize the mean square error between a high bandwidth arterial pressure cardiac output (APCO) measurement generated by a first physiological sensor affixed to a patient and a relatively low bandwidth continuous cardiac output (CCO) measurement generated by a second physiological sensor also affixed to the patient. When calibration parameters are used to adjust an APCO measurement, the combined APCO/CCO estimate provided by the hemodynamic monitor has accuracy comparable to a CCO measurement, but also tracks cardiac output dynamical variations that are outside of the CCO algorithm bandwidth.