What next?
Bytes convert, then get encoded, hashed or timed.
How to use this converter
- Enter a value and its unit (byte, KB, MB and so on).
- Pick the unit to convert to.
- Read the result instantly.
Why your 1 TB drive shows as 931 GB
Storage is sold in decimal units (1 GB = 1,000,000,000 bytes) but operating systems often measure in binary units (1 GiB = 1,073,741,824 bytes) while labelling them "GB". That gap — about 7% — is why a 1 TB drive reports as roughly 931 GiB.
This converter keeps decimal (KB, MB, GB, TB) and binary (KiB, MiB, GiB, TiB) units separate so you can see where the difference comes from.
What your result means
This converter uses decimal (SI) units: 1 kB is 1,000 bytes, 1 MB is 1,000 kB, and so on. That is the convention drive manufacturers, network operators and mobile data plans use, so the result matches the number on the box and on your bill.
Your operating system may disagree. Windows and many file managers report sizes in binary units — 1,024 bytes to the kilobyte — while still writing "MB" and "GB". That is the whole reason a 1 TB drive shows as roughly 931 GB in Explorer: same bytes, different divisor. If you are comparing a file size shown by your computer against a quota or a download limit, check which convention each side is using before you conclude something is missing.
Why this one is different
One entry appears in both unit systems at once, so a decimal figure and its binary counterpart can be read off the same grid without converting twice — useful when a supplier quotes one and your server reports the other. A copyable reference table covers the values you meet most, and the rounding control keeps the exact figure available when a capacity plan needs it.
Frequently asked questions
Is a byte 8 bits?＋
Yes. One byte is 8 bits, so a size in bytes is eight times smaller than the same figure in bits. Internet speeds are usually quoted in bits, file sizes in bytes.
What is the difference between MB and MiB?＋
A megabyte (MB) is 1,000,000 bytes; a mebibyte (MiB) is 1,048,576 bytes. MiB is the binary unit operating systems typically use.
Why does my 1 TB drive show as 931 GB?＋
The manufacturer counts a terabyte as 10 to the power 12 bytes, while the operating system reports in binary units of 1,024. The same drive is 1 TB decimal and about 931 GiB binary, which Windows labels GB.
How do I convert a file size to a download time?＋
Divide the size in bits by the connection speed in bits per second. A 1 GB file is 8,000 megabits, so a 100 Mbps line needs at least 80 seconds, before overheads.
Why are network speeds in bits and files in bytes?＋
Networking has measured throughput in bits per second since the days of serial links, while storage counts bytes. The factor of eight between them catches almost everyone out.
Which prefixes are the official ones?＋
The IEC defines KiB, MiB and GiB for binary multiples, and SI defines kB, MB and GB as powers of 1,000. Software often uses the SI names with binary values, which is where the confusion begins.
Related converters
Conversion reference
Two conventions are in daily use, and they diverge further at every step up.
The binary prefixes (KiB, MiB, GiB) were standardised by the IEC in 1998 precisely to end this ambiguity. Storage manufacturers use decimal; Windows still reports binary while labelling it "GB".
Worked example
Why a 500 GB drive shows as 465 GB:
÷ 1,073,741,824 bytes per GiB
= 465.66 GiB
Nothing is missing — the drive holds exactly what it says. The operating system is dividing by 1,024³ while calling the result "GB".
Assumptions & limitations
Storage figures are more slippery than they look:
- Decimal (1,000-based) and binary (1,024-based) prefixes are both in use. This converter lets you choose; a figure quoted without saying which is ambiguous by up to 10% at terabyte scale.
- Bits and bytes differ by a factor of eight. Network speeds are quoted in megabits per second (Mb/s), file sizes in megabytes (MB) — a 100 Mb/s connection transfers about 12.5 MB per second.
- Formatted capacity is always lower than raw capacity, because the file system itself takes space.
- Advertised drive sizes are decimal by convention and, since a 2006 US settlement, that convention is legally defensible.