Bits to Terabytes Converter

Bits (b). A bit is the smallest unit of digital information: a single 0 or 1. Network speeds and mobile data caps are usually quoted in bits, while file sizes use bytes — eight bits make one byte.

Terabytes (TB). A terabyte here is 1,024 gigabytes. It is used for hard drives, backups and archives; a terabyte holds roughly 250,000 photos or 250 hours of video.

Binary and decimal definitions diverge by about 2.4% at kilo and 7.4% at tera. This converter is binary throughout, so it will not match a manufacturer's decimal specification exactly.

A data conversion looks like the metric chain but is not: this converter uses binary steps, so a kilobyte is 1,024 bytes and a megabyte is 1,024 kilobytes, which is what an operating system reports for a file.

The same names are also used in a decimal system of 1,000, and the gap compounds as the units grow. It is why a drive sold at a round decimal capacity shows less in a file manager, and why a bundle described in decimal gigabytes delivers fewer binary gigabytes than the number suggests.

Checking a data conversion means deciding which definition the number came from before doing the arithmetic. A figure of 500 GB is exact under one definition and about 465 GiB under the other, and no amount of rounding makes those the same quantity.