Data Storage Converter

About the Data Storage Converter

This data storage converter moves file sizes and capacities between bits, bytes and every multiple of both. Storage is the one place where the same prefix genuinely means two different numbers, so rather than silently picking one, the unit list separates them: SI units such as kB, MB and TB step by 1,000, while binary units such as KiB, MiB and TiB step by 1,024. Bits are decimal throughout, matching how networking is quoted, so 100 Mbit really is 100,000,000 bits. Pick the convention your vendor, operating system or config file is using and the answer will match.

How to use the Data Storage Converter

1. 1

   Enter the size or capacity you want to convert in the Value box.

2. 2

   Choose the unit it is currently in from the From list — the byte units and the bit units are listed separately.

3. 3

   Choose your target unit from the To list.

4. 4

   Read the result, and use the table to see the same quantity in every unit from bits to petabytes.

What people use it for

Why 1024 and 1000 both exist

Computers address memory in binary, so capacities naturally fall on powers of two. 2 to the tenth is 1,024, close enough to a thousand that early engineers borrowed the metric prefix kilo and the habit stuck. The SI prefixes, however, are strictly decimal: kilo means exactly 1,000, mega 1,000,000 and so on. Both conventions then continued in parallel, and the discrepancy compounds at every step. At the kilo level the two differ by 2.4 percent; by giga it is 7.4 percent; by tera 10 percent; and by peta 12.6 percent. To end the ambiguity, the IEC introduced binary prefixes in 1998: kibibyte (KiB) for 1,024 bytes, mebibyte (MiB) for 1,024 squared, then gibibyte (GiB) and tebibyte (TiB) above that. Under that scheme KB means 1,000 bytes and KiB means 1,024, with no room for doubt. Adoption in practice is patchy. Linux tooling and RAM specifications generally use the binary quantities, Windows uses binary quantities but labels them KB, MB and GB, and macOS switched to decimal units in 2009 so that a drive's advertised capacity matches what the Finder reports.

The missing space on your hard drive, and bits versus bytes

This explains the most common storage complaint. Drive manufacturers sell in decimal units, so a 1 TB drive genuinely contains 1,000,000,000,000 bytes. Windows divides that by 1,024 three times and reports about 931 GB. No capacity has vanished; the same bytes are simply being counted in larger units and given a smaller number. The shortfall is around 7 percent at gigabyte scale and 10 percent at terabyte scale, with formatting overhead removing a little more on top. The second recurring confusion is bits against bytes. A byte is 8 bits, and the notation distinguishes them by case: a lower-case b means bits and an upper-case B means bytes, so Mb/s and MB/s differ by a factor of eight. Internet providers quote bits per second because it produces a bigger number, which is why a 100 Mb/s connection downloads at a theoretical maximum of 12.5 MB/s, and rather less once protocol overhead is subtracted. One quirk of this particular tool is worth flagging: it applies the 1024 multiplier to the bit units as well, so its kilobit is 1,024 bits rather than the 1,000 bits used in telecommunications.