Byte Converter
Convert units accurately, with the formula shown.
What is the Byte Converter?
This byte converter switches between bits, bytes, kilobytes, megabytes, gigabytes and their binary counterparts (KiB, MiB, GiB), and it keeps decimal and binary units strictly separate instead of quietly treating them as the same thing. Pick "decimal" and a kilobyte is exactly 1,000 bytes, the way storage manufacturers advertise it. Pick "binary" and a kibibyte is exactly 1,024 bytes, the way Windows and macOS actually count. Mixing the two up is the single most common byte-conversion mistake, and it is the reason a "500 GB" drive shows up as roughly 465 GB once you plug it in.
The tool also converts between bits and bytes, which matters for reading internet speeds correctly: your ISP advertises "100 Mbps" in megabits per second, but your download manager reports megabytes per second — a factor of 8 apart, not the same number with a different label.
Why use a free byte converter?
Decimal and binary are never mixed silently
A dedicated toggle switches the whole unit list between the SI (decimal, ×1000) family and the IEC (binary, ×1024) family, so a KB result can never quietly mean KiB.
Bits and bytes both covered
Converts kilobits/megabits (used for network speeds) alongside kilobytes/megabytes (used for file and storage sizes), with the exact 8-bits-per-byte relationship applied.
Exact powers-of-two and powers-of-ten factors
1 GiB is calculated as exactly 1,073,741,824 bytes (2³⁰), and 1 GB as exactly 1,000,000,000 bytes (10⁹) — no rounded approximations in either family.
Explains the mismatch you actually came here to understand
The page states plainly why a drive, phone or cloud plan advertised in one unit shows a smaller number in your operating system.
How do you use the Byte Converter?
- 1
Choose decimal or binary
Decimal (kB, MB, GB…) is how manufacturers advertise storage. Binary (KiB, MiB, GiB…) is how most operating systems report used and free space.
- 2
Enter your value
Type a number into any unit field — bits, bytes, or any prefix in the family you selected.
- 3
Read the converted result
Every other unit in the list updates immediately, calculated from the exact byte count of what you entered.
How is byte converter calculated?
Decimal: 1 kB = 1000¹ B, 1 MB = 1000² B, 1 GB = 1000³ B | Binary: 1 KiB = 1024¹ B, 1 MiB = 1024² B, 1 GiB = 1024³ B | 1 B = 8 bitWhere:
- B
- Byte — 8 bits, exactly
- kB, MB, GB, TB, PB
- Decimal (SI) prefixes — each step is ×1000 bytes
- KiB, MiB, GiB, TiB, PiB
- Binary (IEC) prefixes — each step is ×1024 bytes
- bit, kbit, Mbit, Gbit
- Bits and their decimal multiples — used for data-transfer rates like Mbps
The simple version
A byte is always 8 bits. Beyond that, there are two competing ways to count "a thousand": decimal counts in neat steps of 1,000 (kB, MB, GB), the way you would count money. Binary counts in steps of 1,024 — the nearest round number in base-2 — because computer memory is naturally organized in powers of two. Both systems use similar-looking prefixes (kilo/kibi, mega/mebi, giga/gibi), which is exactly why they get confused: "GB" and "GiB" sound alike but differ by about 7.4%.
What does it look like in practice?
Why a "500 GB" drive shows as ~465 GB
Input
500,000,000,000 bytes (as advertised, decimal GB)
Result
465.66 GiB
Storage makers count in decimal GB (500 × 10⁹ bytes). Windows and macOS report free space in binary GiB. 500,000,000,000 ÷ 1,073,741,824 = 465.66, and the OS usually just labels that number "GB" instead of "GiB" — same bytes, mislabeled unit.
Converting a memory spec
Input
1 MiB
Result
1.048576 MB
1 MiB = 1,048,576 bytes exactly (2²⁰). In decimal terms that is 1.048576 MB — a 4.86% difference from 1 MB, which grows as the numbers get bigger.
Internet speed to download time units
Input
100 Mbps (megabits per second)
Result
12.5 MB/s (megabytes per second)
Divide by 8 to go from bits to bytes: 100 ÷ 8 = 12.5. ISPs advertise the bigger bit number; download managers report the smaller byte number — the connection speed has not changed.
A ripped Blu-ray ISO
Input
4.5 GiB file
Result
4.83 GB
4.5 × 1,073,741,824 = 4,831,838,208 bytes, which is 4.83 GB in decimal terms. A file manager showing "GiB" and a cloud upload page showing "GB" can legitimately show two different numbers for the same file.
How accurate is it?
Every conversion is computed from an exact byte count — decimal prefixes are exact powers of 1000, binary prefixes are exact powers of 1024, and 1 byte is exactly 8 bits. Nothing here is estimated; the only rounding happens when the result is displayed.
- The two prefix families are official standards: SI decimal prefixes (kB = 10³ B) and IEC binary prefixes (KiB = 2¹⁰ B), the latter introduced in 1998 specifically to stop the ambiguity between "kilobyte" meaning 1000 or 1024 bytes.
- Operating systems are inconsistent about which family they use and what they call it — Windows historically labels binary counts with decimal names ("GB" when it means GiB); macOS and most Linux file managers now use decimal GB correctly and label binary values GiB.
- Network speeds are conventionally quoted in decimal bits per second (Mbps, Gbps), never binary — there is no "Mibps" in common use.
What should you know before using it?
The full prefix ladder, decimal next to binary, all relative to 1 byte:
| Decimal (SI) | Binary (IEC) |
|---|---|
| kB — 1,000 bytes | KiB — 1,024 bytes |
| MB — 1,000,000 bytes | MiB — 1,048,576 bytes |
| GB — 1,000,000,000 bytes | GiB — 1,073,741,824 bytes |
| TB — 1,000,000,000,000 bytes | TiB — 1,099,511,627,776 bytes |
| PB — 1,000,000,000,000,000 bytes | PiB — 1,125,899,906,842,624 bytes |
Which tools relate to the byte converter?
The byte converter is one of 14 unit converters on this site. These are the ones most often used alongside it — either because they handle the next step in the same job, or because they answer a question this tool raises.
Bandwidth Calculator
Once you know a file size in the right unit, this works out how long it takes to transfer at a given connection speed.
Unit Converter
The same underlying conversion engine, generalized to length, weight, area, speed and more.
Compress PDF
If you are trying to shrink a specific file rather than just understand its size, this reduces PDF file size directly.
When should you use a byte converter?
Because the byte converter runs entirely in your browser, it suits work you would not want to hand to a third-party server — client files, unpublished drafts, anything under an NDA. These are the situations people reach for it in most often.
Checking real hard drive or SSD capacity
Work out how many GiB a drive advertised in decimal GB will actually show once formatted and mounted.
Estimating download or upload time
Convert an advertised connection speed in Mbps to MB/s to estimate how long a file transfer will realistically take.
Comparing cloud storage and phone plans
Storage tiers and data caps are usually quoted in decimal GB; your device usage meter may report binary GiB, which can make a plan look tighter than it is.
Sizing video, backup and archive files
Convert between MB, GB and their binary equivalents when planning storage for video exports, database backups or disk images.
Frequently asked questions
Is a kilobyte 1000 bytes or 1024 bytes?
Why does my 500 GB or 1 TB drive show less space than advertised?
What is the difference between a bit and a byte?
What does the "i" in KiB, MiB and GiB mean?
How many bytes are in a gigabyte?
How do I convert Mbps to MB/s?
Does this converter round the numbers?
Is the byte converter safe to use?
This tool runs entirely inside your browser. Your text, files and settings are processed on your own device and are never uploaded to our servers — there is nothing for us to store, log or leak. You can confirm it yourself: open your browser DevTools, switch to the Network tab, and use the tool. You will not see an upload request. It also means the tool keeps working if your connection drops mid-task.
Where do these figures come from?
Every method, threshold and standard this page relies on, with a link to the document that defines it. Check them — a tool that will not show its sources is asking you to take its word for it.
- 1Quantities and units — Part 13: Information science and technology
ISO/IEC 80000-13 · 2008
Supports: The binary IEC prefixes (KiB = 2¹⁰ bytes, MiB = 2²⁰ bytes, GiB = 2³⁰ bytes) used throughout the binary conversion family.
- 2Prefixes for Binary Multiples
National Institute of Standards and Technology (NIST)
Supports: The explanation that kibi/mebi/gibi were introduced to remove the ambiguity between the 1000-based and 1024-based meanings of "kilobyte".
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