Terabytes to Gigabits (TB to Gb)

1 terabyte equals 8,000 gigabits exactly.

How to convert terabytes to gigabits

To convert terabytes to gigabits, multiply the number of terabytes by 8,000. This factor is exact. To go the other way, multiply gigabits by 0.000125.

gigabits = terabytes × 8,000

Example: 10 terabytes = 80,000 gigabits.

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

Gigabit (Gb)

ComputingCurrent unit

1,000,000,000 bits (125 MB).

Gigabit is one billion bits, or 125 million bytes. In the IEC notation it is written Gbit, while IEEE 1541-2002 recommends Gb, which may be confused with GB for gigabyte. The binary counterpart, the gibibit, is 2 to the thirtieth bits. Network links and fiber are usually rated in gigabits per second, because data transfer rates are measured in decimal SI multiples.

Memory is where gigabits and binary habits collide. Chip capacity is often given in binary multiples using the ambiguous G prefix rather than the IEC Gi, so a DRAM chip advertised as 1 GB has 2 to the thirtieth bytes. The Wikipedia article on the bit says this was still causing difficulty for software designers as of 2022. When you see a gigabit rate, divide by eight for gigabytes per second.

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

Sources: Wikipedia: Gigabit; Wikipedia: Bit

Related conversions

See all digital storage units.