Terabytes to Terabits (TB to Tb)

1 terabyte equals 8 terabits exactly.

How to convert terabytes to terabits

To convert terabytes to terabits, multiply the number of terabytes by 8. This factor is exact. To go the other way, multiply terabits by 0.125.

terabits = terabytes × 8

Example: 10 terabytes = 80 terabits.

Decimal prefixes (kB, MB, GB) are powers of 1,000; binary prefixes (KiB, MiB, GiB) are powers of 1,024. Storage makers use decimal; Windows reports binary but labels it GB.

About these units

Terabyte (TB)

ComputingCurrent unit

1,000 gigabytes (10¹² bytes), the capacity of a typical modern hard drive.

Tera comes from the SI prefix for 10 to the twelfth, so a terabyte is one million million bytes. Computer memory is binary, so the prefixes were once used for powers of two, which caused confusion. IUPAC proposed binary prefixes such as kibi, mebi and gibi in 1995, and the IEC adopted them in December 1998 and published the standard in January 1999. The tebibyte is the binary counterpart, about 9 percent larger than the terabyte.

Hitachi introduced the first one-terabyte consumer hard drive in 2007. For scale, one terabyte is about 20 standard Blu-ray discs or 213 DVDs. The mismatch shows at this size: a drive sold as 1 TB may be reported as about 931 GB, because Windows uses the historic binary convention. macOS and iOS did the same until Mac OS X 10.5 Leopard and iOS 10, then switched to powers of 10.

1 terabyte = 1,000,000,000,000 bytes (exactly).

Sources: Wikipedia: Terabyte; Wikipedia: Binary prefix; NIST: Prefixes for binary multiples

Terabit (Tb)

ComputingCurrent unit

10¹² bits (125 GB).

Network engineers reach for the terabit because link speeds are quoted in bits per second, and Wikipedia's article on the bit confirms that transfer rates conventionally use decimal SI multiples. One terabit is exactly 10^12 bits, which at eight bits per byte is 125,000,000,000 bytes, or 125 gigabytes. Tera, adopted into the SI in 1960, is the first prefix after giga.

The commonly used symbol is Tbit, and the IEEE 1541 standard recommends lowercase b, giving Tb. That shorthand is risky because capital B means byte, a factor of eight apart. In the IEC naming, a terabit is a decimal unit; its binary counterpart, the tebibit, is 2^40 bits, about 10 percent larger.

Because it is quoted in bits, the terabit suits data rates, where terabits per second describe very high-capacity links, and it is eight times smaller than the terabyte.

1 terabit = 125,000,000,000 bytes (exactly).

Sources: Wikipedia: Bit; Wikipedia: Metric prefix; Wikipedia: Binary prefix

Related conversions

See all digital storage units.