Data Storage Converter
Convert bits, bytes, KB, MB, GB, TB, and PB instantly — with a clear toggle between decimal (1000) and binary (1024) definitions.
Decimal is what storage manufacturers and most spec sheets use. Binary is what operating systems traditionally calculate — this is why a "1 TB" drive shows less than 1 TB of usable space in your OS.
Instant & live
Every unit updates as you type — no "Convert" button, no waiting.
Decimal & binary
Toggle between the two definitions instead of guessing which one applies.
Private by design
Runs entirely in your browser. Nothing is ever uploaded or logged.
Convert Data Storage Units Online
CurePDF's data storage converter converts between bits, bytes, KB, MB, GB, TB, and PB, with an explicit toggle for whether "kilo," "mega," and "giga" mean 1,000 (decimal) or 1,024 (binary) of the unit below them — the two definitions differ, and this converter never conflates them.
Decimal vs. Binary: What's the Difference?
MB (megabyte) uses the decimal definition: 1 MB = 1,000,000 bytes. MiB (mebibyte) uses the binary definition: 1 MiB = 1,048,576 bytes. The two differ by about 5% at the megabyte scale, growing to roughly 10% by the terabyte/tebibyte scale.
Worked example: 5,000,000 bytes is exactly 5 MB in decimal terms, but only approximately 4.77 MiB in binary terms.
Why This Matters
Storage manufacturers (hard drives, SSDs, USB sticks) almost always use the decimal definition on packaging and spec sheets. Operating systems have traditionally reported binary-based sizes while still labeling them KB/MB/GB rather than the more precise KiB/MiB/GiB — which is exactly why a drive advertised as "1 TB" typically shows up as roughly 931 GiB in File Explorer or Finder. Nothing is missing; it's the same bytes measured two different ways.
| Unit | Decimal value | Binary equivalent |
|---|---|---|
| Kilobyte | 1,000 bytes (KB) | 1,024 bytes (KiB) |
| Megabyte | 1,000,000 bytes (MB) | 1,048,576 bytes (MiB) |
| Gigabyte | 1,000,000,000 bytes (GB) | 1,073,741,824 bytes (GiB) |
| Terabyte | 1,000,000,000,000 bytes (TB) | 1,099,511,627,776 bytes (TiB) |
Who Uses a Data Storage Converter?
Developers
Sizing file uploads, database storage, or memory limits precisely.
IT & network admins
Planning storage capacity and reconciling vendor specs against OS reporting.
Students
Learning the real difference between decimal and binary prefixes in computing.
Shoppers
Understanding why an advertised drive size and the OS-reported size don't match.
Common Mistakes When Converting Data Storage
- Assuming a drive is "missing" storage. A "1 TB" drive showing ~931 GiB in your OS isn't a defect — it's the decimal-vs-binary gap.
- Confusing bits and bytes. A lowercase "b" (Mb, Gb) usually means bits, while an uppercase "B" (MB, GB) means bytes — 1 byte = 8 bits, an 8x difference that matters most when comparing storage sizes to network speeds.
- Treating KB and KiB as interchangeable in precise contexts. They're close enough for casual use, but not for exact capacity planning.
Frequently Asked Questions
What is the difference between MB and MiB?
MB (megabyte) uses the decimal definition, 1 MB = 1,000,000 bytes. MiB (mebibyte) uses the binary definition, 1 MiB = 1,048,576 bytes. They differ by about 5%, which is why file sizes can look different between an OS's binary-based reporting and a decimal-based spec sheet.
How many bytes are in a kilobyte?
It depends on which definition you use: 1,000 bytes in the decimal (KB) system, or 1,024 bytes in the binary (KiB) system. Use the toggle on this page to switch between them.
How do I convert MB to GB?
In decimal mode, divide by 1,000. In binary mode, divide by 1,024. For example, 5,000 MB is 5 GB (decimal) or approximately 4.88 GiB (binary).
Which definition do operating systems use?
It varies. Windows File Explorer traditionally reports binary-based sizes (1,024) but labels them KB/MB/GB rather than KiB/MiB/GiB, which is a common source of confusion. Storage manufacturers almost always use the decimal (1,000) definition.