Is a unit of measurement used to describe data. 1MB is 1,000KB (Kilobytes). 1MB is 1,048,576 bytes to be exact but is often rounded off to 1,000,000 bytes. An average length MP3 music file would be about 4MB. A standard photo taken with a 7 Megapixel camera would be 1-1.5MB. A standard 3 page text only Word document would be about .08MB or 80KB.