Terabytes to Megabits (TB to Mb)

1 terabyte equals 8,000,000 megabits exactly.

How to convert terabytes to megabits

To convert terabytes to megabits, multiply the number of terabytes by 8,000,000. This factor is exact. To go the other way, multiply megabits by 1.25×10⁻⁷.

megabits = terabytes × 8,000,000

Example: 10 terabytes = 80,000,000 megabits.

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

Megabit (Mb)

ComputingCurrent unit

1,000,000 bits (125,000 bytes). Internet speeds are advertised in megabits per second.

Megabit is the unit behind most internet plans: speeds are quoted in megabits per second, while files are sized in megabytes. Since a byte is eight bits, a megabit is one eighth of a megabyte, which is 125,000 bytes in decimal units, and an advertised speed in Mbit/s therefore looks eight times larger than the same rate in megabytes per second. Data transfer rates are usually measured in decimal SI multiples.

Writing it is tricky. The IEC symbol is Mbit and the IEEE recommends Mb, but a capital M with lowercase b is easy to confuse with MB, the megabyte. The binary counterpart, the mebibit, is rarely used. Memory chips are sometimes sized in megabits too, so check which unit a spec sheet is using before comparing numbers.

1 megabit = 125,000 bytes (exactly).

Sources: Wikipedia: Bit; Wikipedia: Megabit

Related conversions

See all digital storage units.