Data Storage Converter: KB, MB, GB, TB
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1 GB = 0.001 TB- MB Above the bar: powers of 1000, the way drives, memory cards and phones are sold.
- MiB Below the bar: powers of 1024, the way Windows counts.
A drive sold as 1 GB shows in Windows as about 953 MB.
How much larger each binary unit is:
- 1 KiB = 1.024 KB +2.4%
- 1 MiB = 1.0486 MB +4.9%
- 1 GiB = 1.0737 GB +7.4%
- 1 TiB = 1.0995 TB +10%
- 1 PiB = 1.1259 PB +12.6%
All Results
Quick Reference Table: Gigabyte → Terabyte
| Value (GB) | Result (TB) |
|---|---|
| 0.5 GB | 0.0005 TB |
| 1 GB | 0.001 TB |
| 2 GB | 0.002 TB |
| 4 GB | 0.004 TB |
| 8 GB | 0.008 TB |
| 16 GB | 0.016 TB |
| 32 GB | 0.032 TB |
| 64 GB | 0.064 TB |
| 128 GB | 0.128 TB |
| 256 GB | 0.256 TB |
| 512 GB | 0.512 TB |
| 1,024 GB | 1.024 TB |
About Data Storage Conversions
Data storage units measure digital information. The bit is the smallest unit of data, and 8 bits make one byte. Storage units use either decimal (SI) or binary (IEC) prefixes. In decimal: 1 kilobyte (KB) = 1,000 bytes, 1 megabyte (MB) = 1,000 KB, 1 gigabyte (GB) = 1,000 MB, 1 terabyte (TB) = 1,000 GB. In binary (IEC): 1 kibibyte (KiB) = 1,024 bytes, 1 mebibyte (MiB) = 1,024 KiB, 1 gibibyte (GiB) = 1,024 MiB. Hard drives are usually sold with decimal sizes, while operating systems often show sizes in binary units.
Typical File and Disk Sizes
What actually fits where. Drive makers count 1 GB as 1,000 MB, while operating systems often show binary GiB.
| Item | MB | GB | GiB |
|---|---|---|---|
| Page of plain text | 0.002 | 0.000002 | 0.000001863 |
| eBook | 1 | 0.001 | 0.0009313 |
| MP3 song | 4 | 0.004 | 0.003725 |
| Photo (12 MP JPEG) | 5 | 0.005 | 0.004657 |
| CD | 700 | 0.7 | 0.6519 |
| Hour of HD streaming | 3,000 | 3 | 2.794 |
| DVD | 4,700 | 4.7 | 4.377 |
| 4K movie file | 15,000 | 15 | 13.97 |
| Blu-ray disc | 25,000 | 25 | 23.28 |
| Phone storage (128 GB) | 128,000 | 128 | 119.2 |
| SSD (1 TB) | 1,000,000 | 1,000 | 931.3 |
History of the bit and the byte
Computers count in powers of two, people in powers of ten. The units of digital information grew up between the two, which is why a drive can look smaller on screen than on its label.
- Claude Shannon's paper "A Mathematical Theory of Communication" called the binary digit a bit, a word he credited to John W. Tukey.
- Werner Buchholz, working on IBM's Stretch computer, coined the word byte for a group of bits handled together, at first anywhere from one to six. He respelled "bite" so it could not be misread as "bit".
- IBM's System/360 made its byte 8 bits long, and the machine's success spread that size: since then a byte has generally meant 8 bits.
- The International Electrotechnical Commission approved the binary prefixes kibi, mebi, gibi, tebi, pebi and exbi, so that kilo, mega and giga could keep their decimal meaning.
- Apple's Mac OS X Snow Leopard began reporting storage in decimal units, the way drives are labeled; earlier versions had counted in powers of 1024.
- The General Conference on Weights and Measures added ronna and quetta, the largest SI prefixes so far, expecting them to be needed for amounts of digital data.
Sources:
- Shannon, "A Mathematical Theory of Communication", Bell System Technical Journal (1948) (opens in a new tab)
- Buchholz, "The Word 'Byte' Comes of Age...", Byte (Feb. 1977) (opens in a new tab)
- IBM: System/360 (opens in a new tab)
- NIST: Prefixes for binary multiples (opens in a new tab)
- Apple: How iOS and macOS report storage capacity (opens in a new tab)
- BIPM: 27th CGPM (2022), Resolution 3 (opens in a new tab)