Methods and apparatus to utilize a minimum cross entropy to calculate granular data of a region based on another region for media audience measurement. An example method for calculating granular data of a region for media audience measurement includes determining, by executing first instructions via a processor, aggregate behavioral data associated with a measurement of a media audience of a target region; determining, by executing second instructions via the processor, aggregate demographics data of the target region; and determining, by executing third instructions via the processor, granular data of a source region. The example method includes calculating, by executing fourth instructions via the processor, granular data of the media audience of the target region by utilizing minimum cross entropy to apportion the aggregate demographics data and the aggregate behavioral data of the target region based on the granular data of the source region to determine.