An image forming apparatus includes a sensor that acquires first and second data groups of paper characteristics by measuring a recording medium; a processor that determines a parameter for controlling at least one of image formation and conveyance of a recording medium on a conveyance path based on the first and second data groups acquired by the sensor; an image former that forms an image on a recording medium conveyed on the conveyance path based on the parameter. The processor compares the first and second paper characteristic data groups, the first paper characteristic data group has been measured at a first time period and the second paper characteristic data group has been measured at a second time period nearer to a present time than the first time period, and the processor controls the image formation based on a the comparison result.