A binding device includes a sheet-bundle forming unit; a binding unit that executes a series of operation including inserting a wire into a sheet bundle and bending the wire; a power supply unit; a detector that detects a first timing for transitioning from bending operation to recovery operation; a first timekeeper that measures time from a start point of the series of operation to a first time point, which is an end of a scheduled first-timing detection period; a unit-of-processing manager; and a supply power controller. When the first time point is reached before detection of the first timing, the controller causes the power supply unit to adjust the electric power before the first timing is reached, such that the first timing is detected before the first time point in the series of operation for a second bundle belonging to the same unit of processing as a first bundle.