An image forming apparatus includes a first controller having an image processor that performs image processing on image data, the first controller configured to determine a first statistic value based on the image data, and output the first statistic value; an obtaining unit configured to obtain the image data; an image forming unit configured to form, based on the image data, an image by using toner; a supply unit configured to supply toner to the image forming unit; and a second controller configured to control the supply unit based on the first statistic value. In a case where the first statistic value is not outputted by the first controller in a predetermined period, the second controller controls the supply unit based on a second statistic value, the second statistic value being determined based on the image data.