An image forming apparatus comprises: an image forming section that forms an image on a sheet; a density sensor that measures the image formed on the sheet and outputs a measured value corresponding to a density of the image; a conversion data storing section that stores plural conversion data showing relationship between the measured value outputted from the density sensor and the image density, for each sheet type and each screen for an image; a conversion data selection section that selects at least one conversion data from the plural conversion data stored in the conversion data storing section; and a density adjustment section that adjusts a density for an image formed by the image forming section based on a measured value acquired by measuring a prescribed image formed on a sheet and on the conversion data selected by the conversion data selection section.