Storage unit converter

The confusion between decimal and binary units explains why a 1 TB drive shows up as only 931 GB in your operating system.

Here you can convert between both families and see the gap clearly.

Decimal units (KB, MB, GB) multiply by 1000, while binary ones (KiB, MiB, GiB) multiply by 1024. Operating systems often mix the two conventions.

Kilobyte has two meanings and both are in circulation

In computing, a kilobyte was for decades 1,024 bytes, because powers of two are what matter in memory. Disk manufacturers, by contrast, use a thousand bytes. To untangle it, binary prefixes were created: kibibyte, mebibyte and gibibyte, based on 1,024. Almost nobody uses them outside technical documentation.

Why your drive looks smaller

The manufacturer sells a terabyte counting a trillion bytes. The operating system divides it by 1,024 three times and shows about 931 gigabytes. Nothing is missing: they are two ways of counting the same quantity. The gap grows with size, and on an eight-terabyte drive it is around six hundred gigabytes.

Bits and bytes on your connection

A byte is eight bits. Providers advertise speed in megabits per second while download programs show megabytes per second. A 300 Mbps connection downloads at most around 37.5 MB/s. The lowercase or uppercase b makes all the difference.

Current scales

A petabyte is a thousand terabytes. Large data centres already think in exabytes, which are a thousand petabytes.