An image forming apparatus includes a latent image forming unit that forms an electrostatic latent image on an image carrier based on an image signal, a development unit that includes a circulation mechanism that circulates developer in the development unit and develops the electrostatic latent image using the developer, and a detector unit that detects a toner density of the developer in the development unit. A determination unit determines a replenishment amount of toner to the development unit based on the toner density detected by the detector unit, and a replenisher unit replenishes the development unit with toner based on the determined replenishment amount. The determination unit reduces a predetermined ripple that occurs in accordance with a period of circulation of the developer by executing filter processing for reducing the predetermined ripple.