OomTools

Data File Size Converter

Convert a data size between bytes, KB, MB, GB, TB and PB, switching between binary (1024) and decimal (1000) so the numbers match how your OS or provider counts. Enter one value and see every unit at once. Runs in your browser.

  • 100% free
  • Private & safe
  • Runs in your browser

Why use File Size Converter?

File Size Converter converts instantly and accurately in your browser, showing every unit or format side by side so you can copy the one you need.

  • Runs instantly in your browser — nothing to install, nothing uploaded.
  • Completely free, with no account, no watermarks and no usage limits.
  • Handles Units: B, KB, MB, GB, TB, PB; Bases: 1024 (binary) or 1000 (decimal).
  • Enter an amount and its unit.
  • Works on any device — desktop, tablet and phone — and is fully keyboard accessible.

How to use File Size Converter

  1. Enter an amount and its unit.
  2. Choose binary (1024) or decimal (1000).
  3. Read the value in every other unit.
  4. Copy whichever you need.

Examples

  • Converting 1 GB to MB in both binary and decimal.
  • Checking how many KB are in a 5 MB file.

Supported formats & limits

  • Units: B, KB, MB, GB, TB, PB
  • Bases: 1024 (binary) or 1000 (decimal)

Limitations

  • Binary vs decimal explains why a 1 TB drive shows as ~931 GB in some systems.

Frequently asked questions

Why two bases?

Operating systems often use 1024 while drive makers use 1000, so the same file shows different sizes.

Is it uploaded?

No — it is a local calculation.

Does it handle decimals?

Yes — you can enter fractional amounts like 1.5 GB.

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