Data Size Converter

How to use it

Enter a value and choose the unit it is written in. Every other supported unit's equivalent appears at once and updates on every keystroke, so you can read across the list or copy whichever figure you need. Everything runs in your browser, so nothing is uploaded. The units come in two families that are easy to mix up. Decimal units — kilobytes, megabytes, gigabytes, and terabytes — step up in powers of 1000, so a kilobyte is 1000 bytes and a megabyte is a thousand of those. Binary units — kibibytes, mebibytes, gibibytes, and tebibytes — step up in powers of 1024 instead, so a kibibyte is 1024 bytes. Storage is usually advertised in the decimal family while operating systems tend to report the binary one, and that mismatch is exactly why a drive sold as one terabyte shows up as roughly 931 gibibytes once it is formatted. The tool works in bytes and their multiples, not in bits, so the bit-per-second units used for network speeds such as Kbps and Mbps are not included; if you need bits, divide the byte figure by eight. Type a plain number and, if you like, switch the source unit to see the same amount expressed every other way. As a worked example, one gigabyte is 1,000,000,000 bytes, which is about 0.931 gibibytes, so a drive labelled 500 GB appears as roughly 465 GiB in your operating system. Going the other way, 1024 mebibytes is exactly one gibibyte, and eight megabytes is the size of a one-megabyte-per-second download running for eight seconds. Converting data sizes is useful for understanding real drive and file sizes, estimating how long a download will take, comparing storage plans, and sizing backups. Because the whole conversion happens on your device it is private, and every unit is shown at once so you never have to chain two conversions together.

Frequently asked questions

What's the difference between KB and KiB?

A kilobyte (KB) is 1000 bytes; a kibibyte (KiB) is 1024 bytes. Storage is usually sold in decimal (KB/MB/GB) while operating systems often report binary (KiB/MiB/GiB), which is why a '1 TB' drive shows as about 931 GiB.

Does it convert bits too?

This tool works in bytes and their multiples. Bit-level units (Kbps, Mbps) aren't included; divide bytes by 8 for bits.

Is my data sent anywhere?

No. All conversion happens in your browser; nothing is uploaded.

Why does my drive show less space than advertised?

Drive makers count capacity in decimal units (a 1 TB drive is a trillion bytes), but operating systems usually display binary units, so that same drive reads as about 931 GiB. No space is missing — it is just the same number of bytes shown in a different unit.