Byte converter: KB, MB, GB, TB and KiB, MiB, GiB

Type an amount and its unit. You get every other unit in decimal (1000) and binary (1024) form.

Two systems of units

Computers count in powers of two, but the metric prefixes are powers of ten. That produced two sets of units:

The converter shows both systems for the amount you type. 8 bits make 1 byte, so the bit row is eight times the byte value.

Why a "1 TB" drive shows less on your computer

A drive maker counts 1 TB as 10^12 bytes. Some operating systems divide by powers of 1024 and call the result "GB" or "TB", so a 1 TB drive appears as about 931 "GB". Nothing is missing: the two systems use different sizes of the same word. Windows has traditionally shown binary values with decimal names; other systems show decimal units. Try it: type 1 TB and read the GiB row.

Which unit to use

• Storage and transfer sizes in marketing: decimal (KB, MB, GB).
• Memory (RAM): binary in practice (a "16 GB" module is 16 GiB).
• Technical writing that wants to be exact: use KiB, MiB, GiB for powers of 1024.

Common mistakes

1. Dividing by 1000 when the system uses 1024, or the other way, and finding that the numbers do not match.
2. Confusing bits and bytes. A lower case b is usually a bit and an upper case B a byte. Internet speeds are in bits, file sizes in bytes.
3. Forgetting the capital K and the lowercase k. In SI the kilo prefix is lowercase k, and "KB" with a capital K is the common computer spelling.

This is an independent guide. It is not connected with the IERS, BIPM, IANA, NIST or any company named here. Facts were read on 14 November 2026 from the sources named on each page; calculated values come from Python.