An image forming apparatus that reduces the downtime due to image density control is provided. To accomplish this, the image forming apparatus obtains, using a sensor, background data at a plurality of measurement positions from a rotation member, and density data at a plurality of measurement positions from a patch image formed on the rotation member. Further, the image forming apparatus normalizes density data based on first background data and calculates first correction density data, and also normalizes density data based on second background data for which the measurement positions have been shifted from those of the first background data, calculates second correction density data, and acquires corrected density data in accordance with the first correction density data or the second correction density data that has a smaller variation.