An image forming apparatus includes a punching time measuring unit, a stapling time estimating unit, and a sheet-bundle interval time setting unit. The punching time measuring unit measures a punching processing time to perform punching processing. The stapling time estimating unit calculates an estimated stapling processing time to perform stapling processing by using the punching processing time measured by the punching time measuring unit. The sheet-bundle interval time setting unit sets a sheet-bundle interval time, which is a time from when the last sheet forming a sheet bundle subjected to the punching processing is fed until when the first sheet forming a subsequent sheet bundle subjected to the punching processing is fed.