Digital Storage converter
Convert between any two of 12 digital storage units. Conversion runs in your browser.
More detailsUnits covered · Everyday digital storage conversions · Why a 1 TB drive shows as 931 GB
Units covered
| Unit | Symbol | In bytes |
|---|---|---|
| Byte | B | 1 |
| Kilobyte | KB | 1,000 |
| Megabyte | MB | 1,000,000 |
| Gigabyte | GB | 1,000,000,000 |
| Terabyte | TB | 1,000,000,000,000 |
| Petabyte | PB | 1.000000e+15 |
| Kibibyte | KiB | 1,024 |
| Mebibyte | MiB | 1,048,576 |
| Gibibyte | GiB | 1,073,741,824 |
| Bit | b | 0.125 |
| Megabit | Mb | 125,000 |
| Gigabit | Gb | 125,000,000 |
Everyday digital storage conversions
| 1 of these | B | KB | MB | GB | TB | b |
|---|---|---|---|---|---|---|
| Byte | 1 | 0.001 | 0.000001 | 1.000000e-09 | 1.000000e-12 | 8 |
| Kilobyte | 1,000 | 1 | 0.001 | 0.000001 | 1.000000e-09 | 8,000 |
| Megabyte | 1,000,000 | 1,000 | 1 | 0.001 | 0.000001 | 8,000,000 |
| Gigabyte | 1,000,000,000 | 1,000,000 | 1,000 | 1 | 0.001 | 8,000,000,000 |
| Terabyte | 1,000,000,000,000 | 1,000,000,000 | 1,000,000 | 1,000 | 1 | 8,000,000,000,000 |
| Bit | 0.125 | 0.000125 | 1.250000e-07 | 1.250000e-10 | 1.250000e-13 | 1 |
Each row is one of that unit, given in each of the others.
Why a 1 TB drive shows as 931 GB
Two different definitions of the prefixes are in use. Storage manufacturers use the decimal SI meaning, where a terabyte is 1012 bytes. Operating systems have traditionally used binary multiples, where the same quantity is 240 bytes. The drive is not smaller than advertised; the two systems are counting in different bases, and the gap widens with each prefix — 2.4% at kilo, 7.4% at giga, 10% at tera.
The IEC introduced kibibyte, mebibyte and gibibyte (KiB, MiB, GiB) for the binary meanings so that the SI prefixes could keep their decimal ones. Adoption is partial: Linux tools and macOS report decimal, Windows reports binary while labelling it "GB", and RAM is always sold in binary multiples regardless. Both conventions are available here so you can convert between them explicitly rather than guessing which one a number came from.