Byte / Data Size Converter

What Is a Data Size Unit?

Digital storage and data transfer are measured in bytes, where a single byte is eight bits and typically represents one character of plain text. Because real-world files quickly grow into the millions and billions of bytes, we use larger units — kilobytes, megabytes, gigabytes, terabytes, petabytes and exabytes — to keep the numbers manageable. Each step up the ladder multiplies the previous unit by either 1,000 or 1,024, depending on which standard you follow.

That choice of multiplier is the source of endless confusion. The decimal (SI) convention multiplies by 1,000 and is what storage manufacturers, network providers and the official SI system use: kB, MB, GB, TB. The binary (IEC) convention multiplies by 1,024 (2¹⁰) and has its own names: kibibyte (KiB), mebibyte (MiB), gibibyte (GiB), tebibyte (TiB). Windows still shows binary values with the decimal labels (it calls 1,024 bytes “1 KB”), while macOS and most Linux tools have switched to decimal. The two diverge with every step: at the gigabyte level the gap is about 7 percent, at the terabyte level roughly 10 percent. That is why this converter always shows both side by side.

How to Use This Byte Converter

Type a number into the input field and pick the unit it is in — bytes, a decimal unit (kB … EB), a binary unit (KiB … EiB) or a bit unit (bit … Tbit). The results update as you type: the summary line gives the short answer (for example “134,217,728 bytes = 134.22 MB = 128 MiB”), and the table below lists the exact value in every unit. Each row has a Copy button that copies the plain number without thousands separators, ready to paste into code or a spreadsheet.

You can paste numbers with thousands separators (1,073,741,824 or 1 073 741 824), decimals (2.5) or scientific notation (4e9). Results are shown as ordinary decimal numbers — 0.0001220703125 TiB rather than 1.2207e-4 — and only fall back to exponential notation for truly extreme values. Copy link to this conversion gives you a URL such as /byte-converter/?v=134217728&u=B that opens the tool with the same value, handy for documentation, tickets or chat.

Byte Conversion Table

Exact sizes of each unit in bytes, decimal next to binary:

Decimal unit	Bytes	Binary unit	Bytes
1 kB (kilobyte)	1,000	1 KiB (kibibyte)	1,024
1 MB (megabyte)	1,000,000	1 MiB (mebibyte)	1,048,576
1 GB (gigabyte)	1,000,000,000	1 GiB (gibibyte)	1,073,741,824
1 TB (terabyte)	1012	1 TiB (tebibyte)	1,099,511,627,776
1 PB (petabyte)	1015	1 PiB (pebibyte)	1,125,899,906,842,624
1 EB (exabyte)	1018	1 EiB (exbibyte)	1,152,921,504,606,846,976

Common Conversions

Value	Decimal	Binary
134,217,728 bytes	134.22 MB	128 MiB
1,073,741,824 bytes	1.07 GB	1 GiB
16,384 bytes	16.38 kB	16 KiB
1 TB drive	1,000,000,000,000 bytes	931.32 GiB
500 GB drive	500,000,000,000 bytes	465.66 GiB
4.7 GB DVD	4,700,000,000 bytes	4.38 GiB
128 bits	16 bytes	16 bytes
100 Mbit	12.5 MB	11.92 MiB
1 Gbit	125 MB	119.21 MiB

Real-World Use Cases

• Explaining missing drive space — show why a “1 TB” disk reports as roughly 931 GB in Windows: the drive is sold in decimal terabytes, Windows counts in binary gibibytes.
• Reading byte counts from code and logs — turn a raw value like 134217728 from a config file, an API response or du -b into 128 MiB at a glance.
• Setting limits in config files — find the exact byte value for “64 MiB” to put into upload_max_filesize, a Kubernetes memory limit or a buffer size.
• Estimating download times — internet speeds are quoted in bits; convert a 100 Mbit/s line to 12.5 MB/s before dividing a file size by it.
• Sizing backups and uploads — check whether a 25 GiB folder fits into a cloud plan quoted in decimal gigabytes.

Tips for Working With Data Sizes

• Compare against Windows Explorer or free -h/ls -lh on Linux with the binary column — these tools count in 1,024s even when they print “GB” or “G”.
• Compare against drive packaging, macOS Finder or an internet plan with the decimal column.
• A lowercase “b” means bits, an uppercase “B” means bytes: 100 Mb/s is 12.5 MB/s.
• Memory (RAM) is always built in binary sizes: a “16 GB” module holds 16 GiB = 17,179,869,184 bytes.
• JavaScript numbers are exact up to 2⁵³ (about 9 PB in bytes); beyond that the last digits are rounded.

Features

• 18 units — bytes, decimal kB to EB, binary KiB to EiB and bits from bit to Tbit.
• Both standards at once — decimal and binary results side by side, no switching needed.
• Readable numbers — thousands separators and plain decimals instead of e-notation.
• Copy per value and shareable links — copy any result, or a link that reopens the same conversion.
• 100% client-side — your numbers never leave your browser.

Frequently Asked Questions

Why does my hard drive show less space than advertised?

Storage manufacturers measure capacity in decimal units, so a “1 TB” drive holds 1,000,000,000,000 bytes. Windows reports the same drive in binary units, dividing by 1,073,741,824 per gigabyte, which works out to about 931 GB — the space is not missing, it is just being counted with a different multiplier.

What is the difference between MB and MiB?

A megabyte (MB) is 1,000,000 bytes under the decimal SI standard. A mebibyte (MiB) is 1,048,576 bytes (1,024 × 1,024) under the binary IEC standard. The same split applies to GB/GiB, TB/TiB and so on; the gap grows from 2.4 percent at the kilobyte level to about 15 percent at the exabyte level.

Is 1 KB equal to 1000 or 1024 bytes?

Officially 1 kB is 1,000 bytes and 1 KiB is 1,024 bytes. In practice many programs, Windows included, still write “KB” for 1,024 bytes, so check which standard produced your number. This converter shows both results so you can pick the one that matches.

How many bytes are in a megabyte?

1,000,000 bytes in a decimal megabyte (MB) and 1,048,576 bytes in a binary mebibyte (MiB). For a gigabyte it is 1,000,000,000 versus 1,073,741,824 bytes.

How do I convert bits to bytes?

Divide the number of bits by 8, because one byte has eight bits: 128 bits are 16 bytes, and a 100 Mbit/s connection moves at most 12.5 megabytes per second. Select a bit unit in the dropdown to let the converter do it for you.

Can I link to a specific conversion?

Yes. The page address updates as you type, for example /byte-converter/?v=1&u=TB. Use the “Copy link to this conversion” button and anyone who opens the link sees the same value and unit.

Does this converter send my numbers to a server?

No. Every calculation runs entirely in your browser using JavaScript, so the values you enter never leave your device and nothing is uploaded or stored anywhere.