Data size converter: MB, GB, GiB and bits

Type an amount such as 1 TB in GiB or 500 MB, or type in any field below: every other unit follows. Disks are sold in thousands, Windows counts in 1,024s.

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Convert

Amount and unit

For example 1 TB in GiB, 500 MB, 100 Mbit in MB, 4 GiB in GB.

Answer

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Every unit of a family, together. Choose a family to start from its example; type in any field and the rest follow, and the line above with them. The ring beside a unit makes it the answer.

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Definitions

Thousands: kilo, mega, giga and tera are powers of ten: a kilobyte is 1,000 bytes, a gigabyte 1,000,000,000.BIPM, The International System of Units (SI Brochure), 9th edition: “The SI prefixes refer strictly to powers of 10.”
1,024s: kibi, mebi, gibi and tebi are powers of 1,024: a gibibyte is 1,073,741,824 bytes. Windows counts this way and writes GB.BIPM, The International System of Units (SI Brochure), 9th edition, citing IEC 80000-13.
Bits: 8 bits make a byte. Internet speeds are in bits a second (Mbit/s), file sizes in bytes: the data rate converter turns Mbps into MB/s. Kb, Mb, Gb and Tb (a capital, then a small b) are read as bits, with bytes offered beside the answer; kb, mb, gb and tb as bytes, with bits offered; kB, MB, GB and TB as bytes.Sources read on 10 October 2026.

Disk sizes as Windows shows them

sold as	Windows shows	bytes
128 GB	119.2 GB (GiB)	128,000,000,000 B
256 GB	238.4 GB (GiB)	256,000,000,000 B
512 GB	476.8 GB (GiB)	512,000,000,000 B
1 TB	931.3 GB (GiB)	1,000,000,000,000 B
2 TB	1,862.6 GB (GiB)	2,000,000,000,000 B
4 TB	3,725.3 GB (GiB)	4,000,000,000,000 B

Windows divides by 1,024 three or four times and still writes GB or TB.