Data Storage Converter

Convert a data storage size between decimal units (kB, MB, GB, TB, PB) and binary units (KiB, MiB, GiB, TiB, PiB).

Decimal vs. binary notation

Decimal (SI): kB, MB, GB, TB and PB use powers of 1000 (1 kB = 1000 B). Binary (IEC): KiB, MiB, GiB, TiB and PiB use powers of 1024 (1 KiB = 1024 B). The SI kilo prefix is written with a lower-case k, and Numerila never presents “KB” as if it could mean both. Bits are shown as “bit” and bytes as “B”; megabits are not offered, so MB (megabyte) cannot be mistaken for Mb (megabit).

Worked example

1 kB = 1,000 B but 1 KiB = 1,024 B, so they are different units. 1 GiB = 1.073741824 GB exactly, and 1 TB ≈ 0.9094947018 TiB (its full exact value, 0.9094947017729282379150390625, is shown underneath the result).

How it works

Decimal units (kilobyte to petabyte) are powers of 1000, following the SI convention. Binary units (kibibyte to pebibyte) are powers of 1024, following the IEC convention used by most operating systems when reporting file and disk sizes. A bit is one eighth of a byte. Numerila keeps the two conventions distinct rather than treating “kB” and “KiB” as the same thing. This tool converts unit quantities only: it does not read or upload any file, and it is not a data-rate converter. Enter zero or more: a size cannot be negative.

A result written as a plain number is exact. A result starting with “≈” has been rounded to 10 significant figures, because its exact decimal never ends or is too long to read comfortably. When an exact value is long, its full digits are shown underneath. The calculation itself is never rounded: only the display is.

What this result means

The converted value distinguishes decimal (SI) units from binary (IEC) units, which are not the same size. A plain number is exact; a result starting with “≈” is rounded to 10 significant figures, with the full exact digits shown underneath when they are long.

Common mistakes

Writing "KB" to mean the binary unit of 1,024 bytes. Numerila always labels that unit KiB, and keeps kB for the decimal unit of 1,000 bytes.
Confusing MB (megabyte) with Mb (megabit): this converter offers bytes and bits, not megabits.

Assumptions and limitations

Storage sizes only, not data-transfer rates. Negative values are rejected.

Sources and review

International Electrotechnical Commission (IEC 80000-13) binary-prefix standard