Data Storage Unit Converter
Convert bits, bytes, KB, MB, GB, TB and IEC (KiB, MiB, GiB, TiB) units. Free instant data storage converter.
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All units
| Unit | Value | Copy |
|---|---|---|
| Bitb | 8000000000 | |
| ByteB | 1000000000 | |
| Kilobyte (KB, SI)KB | 1000000 | |
| Megabyte (MB, SI)MB | 1000 | |
| Gigabyte (GB, SI)GB | 1 | |
| Terabyte (TB, SI)TB | 0.001 | |
| Petabyte (PB, SI)PB | 1.000000e-6 | |
| Kibibyte (KiB, IEC)KiB | 976562.5 | |
| Mebibyte (MiB, IEC)MiB | 953.67432 | |
| Gibibyte (GiB, IEC)GiB | 0.93132257 | |
| Tebibyte (TiB, IEC)TiB | 0.0009094947 |
Popular conversions
How data size conversion works
A byte is 8 bits. Above that there are two systems. Decimal (SI) prefixes go up in thousands: 1 KB = 1,000 bytes, 1 MB = 1,000,000 bytes, 1 GB = 10⁹ bytes. Binary (IEC) prefixes go up in powers of 1,024: 1 KiB = 1,024 bytes, 1 MiB = 1,048,576 bytes and 1 GiB = 1,073,741,824 bytes. The IEC approved the binary names in December 1998 to end the ambiguity.
Drive makers and network speeds use decimal units. Many operating systems divide by 1,024 but still print 'GB', which is why a new drive seems smaller than its label. This converter keeps the two systems separate so you can see both.
Worked examples
Why a 1 TB drive shows 931 GB
1 TB = 10¹² bytes. 10¹² ÷ 1,073,741,824 = 931.3 GiB. Nothing is missing; it is the same number of bytes counted in binary units.
Phone storage
A 256 GB phone holds 256 × 10⁹ bytes, which a computer reports as 238.4 GiB.
Download time from a megabit speed
Internet speeds are in megabits per second. 100 Mbps ÷ 8 = 12.5 MB/s, so a 5 GB file takes 5,000 MB ÷ 12.5 = 400 s, a little under 7 minutes, before overhead.
Advertised sizes (decimal) and what the computer shows (binary)
| GB | MB | GiB | MiB | |
|---|---|---|---|---|
| 1 GB | 1 | 1,000 | 0.931323 | 953.674 |
| DVD (4.7 GB) | 4.7 | 4,700 | 4.37722 | 4,482.27 |
| 64 GB card | 64 | 64,000 | 59.6046 | 61,035.2 |
| 256 GB phone | 256 | 256,000 | 238.419 | 244,141 |
| 500 GB drive | 500 | 500,000 | 465.661 | 476,837 |
| 1 TB drive | 1,000 | 1,000,000 | 931.323 | 953,674 |
| 2 TB drive | 2,000 | 2,000,000 | 1,862.65 | 1,907,350 |
Common mistakes
- Confusing bits and bytes. Mb (megabit) is one-eighth of MB (megabyte). Divide a Mbps speed by 8 for MB per second.
- Assuming GB always means 1,024 MB. In the SI system it means 1,000 MB; the 1,024 version is properly called GiB (NIST, IEC 60027-2).
- Expecting the full labeled capacity to be free. Formatting and system files take space on top of the decimal-versus-binary difference.
Sources
Conversion charts
Frequently asked questions
Is 1 GB equal to 1000 MB or 1024 MB?
In the SI system 1 GB = 1,000 MB. In the IEC binary system, 1 GiB = 1,024 MiB. Hard drives are sold in SI; operating systems often report in IEC.
Why does my 1 TB drive show 931 GB?
Manufacturers measure 1 TB as 1,000,000,000,000 bytes. Operating systems show that as ~931 GiB (binary).
What is the difference between Mb and MB?
Mb is megabits and MB is megabytes. A byte is 8 bits, so 1 MB = 8 Mb, and a 100 Mb/s connection moves 12.5 MB per second.
How many bytes are in a kilobyte?
1,000 bytes (KB, SI) or 1,024 bytes (KiB, binary).
How long does it take to download 1 GB at 50 Mbps?
1 GB is 8,000 megabits, so 8,000 ÷ 50 = 160 s, about 2.7 minutes, before protocol overhead.