A measuring device including a sensor that generates data representing a detected body parameter, such as body fat, body water and weight of an individual. A portable device removably connected to the measuring device for receiving, displaying and storing the data representing the detected body parameter. The portable device may correlate the stored data with an individual user. The portable device is responsive to a personal computer for uploading the stored information thereto. The portable device includes a calibration unit for calibrating the measuring device.