We use an average photo file size of 2MB for our calculation. We picked this size for our calculation because it is the approximate size of an 8MP photo saved in a .JPEG format. Some file sizes are much larger, such as camera RAW files, movie files such as .MOV and .MPEG4, and photos taken with cameras that can take photos greater than 8MP, so the number of photos that can be stored on ThePhotoStick Mobile can vary.