Abstract: An apparatus is disclosed for measuring the tension in a belt. The preferred embodiment incorporates a housing which is adapted to be momentarily attached to a belt. As the belt tension is varied, the device indicates the change in tension. This is achieved by incorporating a roller which contacts the belt, the roller supporting a pointer or needle which gives a reading by its movement adjacent to a scale on a housing. The housing is held secure to the belt by a clamping means contacting one edge against the belt. The housing is additionally supported against the belt by the roller which is supported on a shaft in the housing. The roller thus rotates on elongation, and the needle deflects.