Abstract: A sheet counting apparatus includes a set of rotatably mounted suction spindles mounted for movement past a stack of sheets to be counted. A pump is connected to the spindles whereby a suction spindle passes the stack, a vacuum is supplied to the spindle so that the topmost sheet is deflected from its initial position. A monitoring system monitors the number of deflected sheets by monitoring the degree of vacuum within the suction spindle passing the stack. The monitoring system increments a count on each occasion when the monitored vacuum exceeds a predetermined threshold. The monitoring system terminates the count process when a predetermined period is exceeded without the vacuum exceeding the predetermined threshold, the predetermined period corresponding to the passage of at least two spindles past the stack of sheets, without the spindles deflecting a sheet.