Storage units can mean two slightly different things depending on context: operating systems and most software (including this converter) use the binary convention, where each step up is ×1,024, while some drive manufacturers advertise capacity using the decimal convention, where each step is ×1,000. That mismatch is why a "1TB" drive shows up as roughly 931GB in your operating system.
How it works
This converter uses the binary convention: 1 KB = 1,024 bytes, 1 MB = 1,024 KB, and so on up through PB, matching what your operating system reports for file and drive sizes.
Conversion works by first converting your input to bytes (multiplying by 1,024 raised to the power matching the source unit), then dividing by 1,024 raised to the power matching the target unit.
The technically precise names for binary units are KiB, MiB, GiB, etc. (kibibyte, mebibyte, gibibyte), but KB, MB, and GB are used almost universally in everyday software to mean the same binary values this converter uses.
A worked example
1 GB converts to exactly 1,024 MB, or 1,073,741,824 bytes, the number you'd see if you checked a 1GB file's exact size in a file manager.
Questions people ask
Why does my hard drive show less space than advertised?
Drive manufacturers typically advertise capacity using the decimal convention (1TB = 1,000,000,000,000 bytes), while your operating system reports size using the binary convention (1TB = 1,099,511,627,776 bytes). The drive isn't missing storage. It's the same number of bytes, described two different ways, which is why a "1TB" drive shows as roughly 931GB in Windows or macOS.
What's the difference between KB and KiB?
They represent the same binary value (1,024 bytes). KiB (kibibyte) is the International System-approved unambiguous name, introduced specifically to resolve the KB decimal-vs-binary confusion. In practice, most consumer software still uses "KB" to mean what is technically a KiB, which is the convention this converter follows.
How many bytes are in a bit, and does this converter handle bits?
A byte is 8 bits. This converter works in bytes and its multiples (KB, MB, GB, etc.); network speeds are often quoted in bits per second (Mbps) rather than bytes, which is a common source of confusion when estimating download times from a connection speed.