Data Size Converter: Bytes, KB, MB, GB, KiB, MiB, GiB

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  • No sign-up
  • Runs in your browser
  • Last updated 2026-10-07
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Enter a size in any unit and see it in bits, bytes, and both the decimal and the binary units.

Bits and bytes

bit
byte (B)

Decimal units (1 kB = 1000 bytes)

kilobyte (kB)
megabyte (MB)
gigabyte (GB)
terabyte (TB)
petabyte (PB)

Binary units (1 KiB = 1024 bytes)

kibibyte (KiB)
mebibyte (MiB)
gibibyte (GiB)
tebibyte (TiB)
pebibyte (PiB)

Everything you enter is processed in your browser and is never sent to a server.

How to use

  1. Enter the size and choose its unit. Gigabyte is selected at first.
  2. Read the size in every unit. The decimal group uses powers of 1000 and the binary group uses powers of 1024.
  3. Copy the value you need with its Copy button.

Examples

1 GB
→ 1,000,000,000 bytes, which is 0.9313225746 GiB
1 GiB
→ 1,073,741,824 bytes, which is 1.073741824 GB
1 TB
→ 931.3225746 GiB
This is why a 1 TB drive shows as about 931 GB in an operating system that counts in powers of 1024.

How it works

Your size is first converted to bytes by multiplying with the size of its unit, and then divided by the size of each other unit. A bit is one eighth of a byte, decimal units are 1000, 1,000,000, and so on, and binary units are 1024, 1,048,576, and so on.

Results are rounded to ten significant digits so that numbers such as 1048.5760000000001 are written as 1048.576. The conversions are exact for the sizes people normally enter, and the factors are covered by tests, for example 1 GB equals 1,000,000,000 bytes and 1 GiB equals 1,073,741,824 bytes.

Sources

Frequently asked questions

What is the difference between GB and GiB?
GB (gigabyte) is 1000 x 1000 x 1000 bytes. GiB (gibibyte) is 1024 x 1024 x 1024 bytes, about 7.4% more. The prefixes kilo, mega and giga mean powers of 1000 in the SI system, and kibi, mebi and gibi were created by the IEC to mean powers of 1024.
Why does my drive show less space than the box says?
Drive makers count in powers of 1000, so 1 TB is 1,000,000,000,000 bytes. Some operating systems count in powers of 1024 and, as Windows does, label the result GB, so the same drive shows as about 931 GB. macOS counts in powers of 1000.
What is the difference between a bit and a byte?
A byte is 8 bits. Network speeds are usually given in bits per second (Mbps) and file sizes in bytes, so a 100 Mbps connection moves at most 12.5 megabytes per second.
Which should I use, kB or KiB?
Use the one that matches the system you are describing. For memory and many file systems, binary units are the accurate ones. For storage devices and network speeds, decimal units are standard. Writing the symbol correctly avoids confusion.
Is my number sent anywhere?
No. The conversion is done in your browser.

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