Why does my 1TB drive show up as less than 1TB in my file explorer?

Drive manufacturers use decimal units (1TB = 1000GB), but most operating systems display binary units (1TiB ≈ 1024GiB) while still calling them GB/TB — the drive isn't missing space, the units just don't match.

Which unit should I use for file sizes — decimal or binary?

Binary (KiB/MiB/GiB) is technically precise for how computers actually allocate memory and storage internally; decimal (KB/MB/GB) is what most consumer software displays, so match whichever context you're comparing against.

Can I convert in both directions?

Yes, enter a value in any unit and see it converted to all the others simultaneously.

Does File Size Converter upload my files to a server?

No. File Size Converter runs entirely in your browser using on-device processing, your files never leave your device.

File Size Converter

Convert between bytes, KB, MB, GB, and their binary (KiB/MiB/GiB) equivalents.

Runs in your browser

AmountUnit

Bytes1,000,000

Kilobytes (KB)1,000

Megabytes (MB)1

Gigabytes (GB)0.001

Kibibytes (KiB)976.5625

Mebibytes (MiB)0.953674

Gibibytes (GiB)0.000931

About this tool

File sizes get reported in two competing systems that look almost identical but aren't: the decimal units operating systems and storage vendors often use (1 KB = 1000 bytes) and the binary units most software actually calculates with (1 KiB = 1024 bytes) — which is exactly why a drive advertised as 1TB shows up as roughly 931GB in your file explorer. This tool converts between bytes, KB/MB/GB and their binary KiB/MiB/GiB equivalents, so you can figure out exactly what a given file size means in whichever unit you're comparing it against.

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