What is a megabyte (MB)?

Megabyte (MB) is a data-measurement unit for computer storage that is approximately a million bytes of information. Though 1,000,000 bytes (i.e. Base 10) is the most common conversion used by storage companies, Base 2 (1MB = 1,048,576 bytes) is used by Microsoft Windows. This is why drives show a smaller capacity than what is shown on the box. For example, drives will appear as 232GB, and 931GB for the advertised 250GB and 1TB, respectively.

The mixed conversion rate is 1MB = 1,024,000 bytes, which, in this context, is used to refer to the formatted capacity of the 1.44MB, 3.5-inch floppy disk.

Unit (Base 10)

  • 1,000MB = 1GB (gigabyte)
  • 1,000,000MB = 1TB (terabyte)