To provide an image forming apparatus that determines the addition amount of fluorescent whitening agent that improves the whiteness of a recording medium, in consideration of the inherent whiteness of the recording medium.

An image forming apparatus 1 includes: a sheet information input part 22 that obtains the whiteness of a sheet P, which is used for image formation by an image forming unit 13, as the sheet whiteness; a fluorescent whitening agent usage purpose setting part 21 that obtains the whiteness required for the sheet P after image formation as the target whiteness; a fluorescent whitening agent addition amount determination part 23 that determines the addition amount of the fluorescent whitening agent added to the sheet P based on the sheet whiteness and the target whiteness; and a fluorescent whitening agent addition part 24 that adds the fluorescent whitening agent that improves the whiteness of the sheet P.