Abstract: A body composition analyzer comprises a pair of handgrips extending laterally from either side of a housing containing other components of the device. Each handgrip comprises two electrodes positioned to make contact with a subject's hands when grasped. A source of low voltage, high frequency alternating current is connected across first electrodes on each handgrip, so as to form a circuit passing through the subject's body, and an impedance measuring instrument is connected to the second electrodes on each handgrip, to measure the impedance of the body in the circuit. The instrument also comprises a keypad for receiving data entered manually by the subject defining physical characteristics such as age, gender, height, weight, and the general physical condition of the subject. The input data is used to select one of a set of coefficients developed by regression analysis for use in an equation relating total body water to the impedance value and to the subject's total body water content.