Gibibytes to Mebibytes (GiB to MiB)

1 gibibyte equals 1,024 mebibytes exactly.

1 gibibyte = 1,024 mebibytes

How to convert gibibytes to mebibytes

To convert gibibytes to mebibytes, multiply the number of gibibytes by 1,024. This factor is exact. To go the other way, multiply mebibytes by 0.0009765625.

mebibytes = gibibytes × 1,024

Example: 10 gibibytes = 10,240 mebibytes.

Decimal prefixes (kB, MB, GB) are powers of 1,000; binary prefixes (KiB, MiB, GiB) are powers of 1,024. Storage makers use decimal; Windows reports binary but labels it GB.

About these units

Gibibyte (GiB)

ComputingCurrent unit

Exactly 1,073,741,824 bytes (2³⁰), about 7.4% larger than a gigabyte. Windows displays this as 'GB', which is why a 500 GB drive appears as about 465 GB.

Gibibyte is the unit that explains why a new drive looks smaller than its box says. It is the IEC name, from December 1998, for 2 to the thirtieth bytes, or 1,073,741,824 bytes, chosen to denote powers of 1,024 unambiguously. A GiB is about 7.4 percent larger than a decimal gigabyte, so a drive advertised as 500 GB holds 500 billion bytes, which is about 465.7 GiB.

Windows reports that number with the label GB, so users see a shortfall. RAM is still counted in the binary sense, while hard drives, SSDs, flash media and optical discs are usually labeled in decimal units. Courts have held that the legal definition of GB is the decimal one. The symbol GiB is formed by adding an i to GB, and apart from KDE and Qt-based applications it is rarely used in practice.

1 gibibyte = 1,073,741,824 bytes (exactly).

Sources: Wikipedia: Gibibyte; NIST: Prefixes for binary multiples

Mebibyte (MiB)

ComputingCurrent unit

Exactly 1,048,576 bytes (2²⁰). The binary megabyte, about 4.9% larger than a decimal megabyte.

Mebi, from mega with the binary i added, belongs to the same 1998 IEC family as kibi and gibi, which the IEC published as Amendment 2 to IEC 60027-2 in January 1999. NIST gives the factor as 2 to the twentieth, or 1,048,576 bytes. It was meant to settle a real argument: once storage makers and telecom engineers used decimal values and programmers used binary ones, megabyte came to mean different amounts.

A mebibyte is about 4.9 percent larger than a megabyte, and the standard is now IEC 80000-13. The classic example is the 1.44 MB floppy, whose true capacity is 1,440 KiB, which is 1.47 MB or 1.41 MiB. Like other IEC symbols, MiB is rarely used outside tools such as KDE and Qt-based applications, while Windows and RAM labels use MB for the binary quantity.

1 mebibyte = 1,048,576 bytes (exactly).

Sources: NIST: Prefixes for binary multiples; Wikipedia: Mebibyte

Related conversions

See all digital storage units.