Byte

A byte is a unit of measurement. One byte is usually equal to eight bits. Technically, some old computers had bytes with different numbers of bits. An octet is always eight bits. One byte can be any number from 0 to 255. Bytes are used when talking about the size of computer, or other electronic data (information).

Abbreviation

"Byte" is properly abbreviated as uppercase "B".

Sometimes it is incorrectly abbreviated as lowercase "b"; lowercase "b" is the abbreviation for "bit". For example, "MB" means "megabyte" and "Mb" means "megabit". The difference is important because 1 megabyte (MB) is 1,000,000 bytes, and 1 megabit (Mb) is 1,000,000 bits. It's easy to confuse the two, but bits are much smaller than bytes, so a lowercase "b" should be used when referring to "bits" and an uppercase "B" when referring to "bytes".

Names for larger units

For large data, byte is often used with a binary prefix:

• Kilobyte/kibibyte
• Megabyte/mebibyte
• Gigabyte
• Terabyte/tebibyte
• Petabyte/pebibyte
• Exabyte/exbibyte
• Zettabyte
• Yottabyte

Byte Chart

According to the International Electrotechnical Commission (IEC), who sets many computer standards, these charts show how bytes should be referred to.

"kilo-" = 1,000 bytes

When using standard metric names like "kilo-", "mega-" and "giga-", they should follow the same measure that other metric measurements use, like kilometer (1 kilometer = 1,000 meters) for example.

Byte (B)	1	1 byte
Kilobyte (KB)	1,000	1 thousand bytes
Megabyte (MB)	1,000,000	1 million bytes
Gigabyte (GB)	1,000,000,000	1 billion bytes
Terabyte (TB)	1,000,000,000,000	1 trillion bytes
Petabyte (PB)	1,000,000,000,000,000	1 quadrillion bytes
Exabyte (EB)	1,000,000,000,000,000,000	1 quintillion bytes
Zettabyte (ZB)	1,000,000,000,000,000,000,000	1 sextillion bytes
Yottabyte (YB)	1,000,000,000,000,000,000,000,000	1 septillion bytes

"kibi-" = 1,024 bytes

Since most computers are digital devices that are based on the binary numeral system rather than the commonly-used decimal numeral system or binary coded decimal system, there are many situations where the standard metric system does not work well, particularly with USB drives and other types of flash memory or RAM. If a memory or storage device uses a binary number for addresses, the number of different positions to be accessed can be expressed as a power of 2, rather than a power of 10.

People who refer to 1 kilobyte as 1,024 bytes, for example, are technically incorrect; 1,024 bytes should be referred to as 1 kibibyte, according to the IEC.

Byte (B)	1	20 bytes
Kibibyte (KiB)	1,024	210 bytes
Mebibyte (MiB)	1,048,576	220 bytes
Gibibyte (GiB)	1,073,741,824	230 bytes
Tebibyte (TiB)	1,099,511,627,776	240 bytes
Pebibyte (PiB)	1,125,899,906,842,624	250 bytes
Exbibyte (EiB)	1,152,921,504,606,846,976	260 bytes
Zebibyte (ZiB)	1,180,591,620,717,411,303,424	270 bytes
Yobibyte (YiB)	1,208,925,819,614,629,174,706,176	280 bytes