Data storage converter

Convert between bytes, kB, MB, GB, TB and their binary cousins KiB, MiB, GiB and TiB.

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About this tool

Convert a quantity of data between bits, bytes, kilobytes, megabytes, gigabytes, terabytes and petabytes, and between the binary units — kibibytes, mebibytes, gibibytes and tebibytes — that operating systems actually count in. Both families are shown side by side, which explains why a drive sold as 1 TB appears as 931 GB once it is plugged in. Every unit is listed at once, so you can read off the one you need without converting twice.

Helpful answers

Using this tool

Why does my 1 TB drive show as 931 GB?

Because the two numbers count differently. The manufacturer means 1,000,000,000,000 bytes; Windows divides by 1,024 three times and calls the result GB, when it is strictly gibibytes. No space is missing — 931 GiB and 1 TB are the same number of bytes.

What is the difference between MB and MiB?

A megabyte is 1,000,000 bytes; a mebibyte is 1,048,576. The gap is 4.9% at mega and grows with each step: 10% at tera. macOS and most storage vendors use the decimal units, Windows and Linux tools usually report binary ones.

Why is my 100 Mb/s connection only downloading at 12 MB/s?

It is not slow — those are different units. Network speeds are quoted in bits per second and file managers report bytes per second, and there are eight bits in a byte. 100 Mb/s is 12.5 MB/s at its theoretical best.

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