A wrist-wearable body composition measuring device includes a main body; a strap connected to the main body; a first input electrode and a first output electrode which are provided on an inner surface of the strap and configured to contact a wrist of a subject; a second input electrode and a second output electrode which are provided on an outer surface of the strap; a measuring unit configured to measure a body impedance of the subject by applying current to the first input electrode and the second input electrode and detecting a voltage generated between the first output electrode and the second output electrode in response to the applied current; and a processor configured to analyze a body composition of the subject based on the body impedance measured by the measuring unit.