A body analyzer includes a main body including a platform contacting feet of a subject, an information transmitter, a weighing and body analyzing mechanism, a signal processor, and a wireless communication device, and a detecting board abutting against the subject's top head. At least one of the main body and the detecting board has a signal emitter, and at least one of the two has a signal receiver, thereby measuring a distance between the platform and the detecting board. The information transmitter emits data of the signal emitter and the signal receiver to the weighing and body analyzing mechanism. The weighing and body analyzing mechanism calculates body compositions of the subject. The signal processor processes data from the signal emitter, the signal receiver, and the weighing and body analyzing mechanism. The wireless communication device emits a processed data to an external mobile device or server via a wireless network.
