File Size Calculator
Convert between bytes, KB, MB, GB, TB and bits instantly
Storage Units (binary, ×1024)
Network / Bit Units (decimal, ×1000)
Click any row to copy the value
About the File Size Converter
This file size converter moves between bytes, KB, MB, GB and TB, and shows both the decimal and binary interpretations. That distinction is why a "500 GB" drive shows up as roughly 465 GB in your operating system.
A file size converter answers the everyday question of whether something fits — under an email limit, within a hosting quota, or on a given drive. Sizes are quoted in different units by different tools, so converting is constant.
The decimal-versus-binary split is the interesting part. Storage manufacturers use decimal units where a kilobyte is 1,000 bytes; operating systems traditionally use binary units where it is 1,024. The gap compounds with scale: about 2% at the kilobyte, roughly 7% by the gigabyte and close to 10% at the terabyte — which is the entire explanation for a 500 GB drive reporting 465 GB.
The formally correct binary names are KiB, MiB and GiB, though almost nobody uses them consistently. Both interpretations are shown here so you can tell which one a given number came from.
How to use the File Size Converter
- Enter the size. Type the value you have.
- Set the input unit. Choose bytes, KB, MB, GB or TB.
- Read the conversions. See the equivalent in every other unit.
- Compare decimal and binary. Check both interpretations to see which matches your source.
File Size Converter features
- Converts between bytes, KB, MB, GB and TB
- Decimal (1000) and binary (1024) interpretations side by side
- Every other unit calculated at once
- Copy any value
- Runs in your browser; nothing is uploaded
Frequently asked questions
Why does my 500 GB drive show as 465 GB?
Because the manufacturer counted in decimal units and your operating system is counting in binary ones. 500,000,000,000 bytes divided by 1,024 three times is 465.7, so both numbers describe the same drive. Nothing is missing and nothing is faulty.
What is the difference between KB and KiB?
A kilobyte (KB) is 1,000 bytes and a kibibyte (KiB) is 1,024. The KiB, MiB and GiB names were introduced precisely to end this ambiguity, but adoption has been patchy, so plenty of tools still print KB while meaning 1,024.
Which interpretation should I use?
Match whatever produced your number. Drive capacities, network speeds and cloud storage quotas are quoted in decimal; file sizes in Windows, Linux and macOS disk utilities are usually binary. Guessing wrong is how a file that should fit does not.
How large does the discrepancy get?
It compounds by a factor of 1.024 at each step: around 2% at the kilobyte, 5% at the megabyte, 7% at the gigabyte and nearly 10% by the terabyte. That is why the mismatch feels negligible on small files and obvious on drives.
Is anything uploaded?
No. This is arithmetic done in your browser — no file is involved at all, only the number you type.