What is the abbreviation for kilobyte?

"kilobyte" is abbreviated in a number of ways: KB, kB, K and Kbyte.

Lowercase "k" often implies the standard SI prefix of kilo-, which means 1,000 bytes. This is the way it's used in scientific or engineering contexts, disk media, networking, etc.

Uppercase "K" often implies that the unit refers to 1,024 bytes, a power of 2, used in measuring memory, etc. This is officially wrong, and should be written "KiB" instead.

It is sometimes abbreviated with a lowercase b ("kb"), but this is discouraged, because it is ambiguous with kilobit. It's recommended to abbreviate "byte" as "B" and "bit" as "bit" (which is already an abbreviation for "binary digit" anyway.)

• "1 kB" = 1000 bytes
• "1 KB" = 1024 bytes (probably)
• "1 KiB" = 1024 bytes (definitely)
• "1 kbit" = 1000 bits