An apparatus and method for determining stroke volume by bioimpedance from a person that includes two or more spaced apart alternating current flow electrodes positionable on a persons forearm, two or more spaced apart voltage sensing electrodes positionable on the persons forearm and between the alternating current flow electrodes, an alternating current source providing an alternating current to the current flow electrodes, a voltmeter configured to generate a voltage signal from a voltage sensed by the voltage sensing electrodes, and a processing unit configured to determine a stroke volume (SV) using the voltage signal and at least one of two equations that include, among other terms, the persons weight, a peak time rate of change of a transradioulnar impedance pulse variation (dZ/dtmax), a transradioulnar quasi-static base impedance (Z0), a systolic flow time (TSF), and a volume conductor (Vc).