What is mebibyte (binary)?

A mebibyte is a binary data unit equal to 1,024 kibibytes, or 1,048,576 bytes. It is used in operating systems, RAM specifications, and software contexts where exact binary data sizes are required.

Real-world uses

Mebibytes are used by operating systems when reporting RAM size and filesystem usage. Windows Task Manager and Linux tools such as "free" and "df" report memory in MiB. RAM sticks are specified in binary multiples; a "4 GB" RAM module is actually 4 GiB = 4,096 MiB.

History

The mebibyte was standardised by the IEC in 1998 alongside the kibibyte and gibibyte to eliminate the ambiguity created by the historical use of "megabyte" to mean either 1,000,000 or 1,048,576 bytes. Adoption has been gradual, with the Linux kernel and many technical tools now using MiB correctly.

Common mistakes

Confusing MiB (mebibyte, 1,048,576 bytes) with MB (megabyte, 1,000,000 bytes). A mebibyte is approximately 4.86% larger than a megabyte. Software that reports in MiB may appear to show less space than marketing specifications that use MB.

What is byte?

A byte is a fundamental unit of digital information, typically comprising 8 bits. It is the standard unit for measuring file size, storage capacity, and data transfer quantities in computing.

Real-world uses

The byte is the fundamental unit of digital information. File sizes, RAM capacity, hard drive storage, and network data quotas are all measured in bytes and their multiples. A byte is 8 bits and can represent 256 distinct values. Text encoding stores approximately 1 byte per ASCII character.

History

The term "byte" was coined by Werner Buchholz in 1956 while working at IBM on the Stretch computer. He defined it as a group of bits processed together. The 8-bit byte became standard with IBM System/360 in 1964 and has remained the universal digital unit since.

Common mistakes

Confusing bytes (B) with bits (b) — internet speed is often quoted in megabits per second (Mbps), while file sizes are in megabytes (MB). Downloading a 10 MB file at 10 Mbps takes about 8 seconds because 10 MB = 80 Mb.

When is this conversion used?

Operating systems and storage manufacturers use different base systems (binary vs decimal), which is why a '1 TB' drive shows less than 1 TB in your file manager. Understanding this conversion prevents confusion about available storage.

Worked examples

1 mebibyte (binary) = 1,048,576 byte

1 byte = 1 byte

How to convert mebibyte (binary) to byte

To convert mebibyte (binary) to byte, multiply the value by 1,048,576.

To convert byte back to mebibyte (binary), multiply by 9.536743e-07.

Measurement standards

The International Electrotechnical Commission (IEC 80000-13) defines binary prefixes: 1 KiB = 1,024 bytes, 1 MiB = 1,048,576 bytes. The SI decimal prefixes (kB = 1,000 bytes, MB = 1,000,000 bytes) apply to data units as they do to all SI quantities.

Did you know?

By 2025, the global datasphere is estimated to reach 181 zettabytes — roughly 181 trillion gigabytes. If stored on standard Blu-ray discs, the stack would reach from Earth to Mars and back over 20 times.

Quick reference: mebibyte (binary) to byte

mebibyte (binary)byte
0.1104,857.6
0.5524,288
11,048,576
22,097,152
55,242,880
1010,485,760
2526,214,400
5052,428,800
100104,857,600
250262,144,000
500524,288,000
1,0001.048576e+09

Common values

mebibyte (binary)byte
A text email0.00476837 mebibyte (binary)5,000 byte
An MP3 song (4 min)3.81469727 mebibyte (binary)4,000,000 byte
A smartphone photo4.76837158 mebibyte (binary)5,000,000 byte
An HD movie4,768.37158203 mebibyte (binary)5.000000e+09 byte
A full hard drive953,674.31640625 mebibyte (binary)1.000000e+12 byte