Data Storage Unit Converter

Data Storage Unit Converter

Digital storage is measured in more units than most people realize, and two of them - the decimal (SI) prefixes like KB/MB/GB and the binary (IEC) prefixes like KiB/MiB/GiB - don't mean the same thing even though they look almost identical. This tool converts a value between any two of these units and shows the same value expressed in every unit at once, so you can see exactly how they relate.

Decimal vs binary units

Storage vendors (hard drives, SSDs, cloud storage plans) advertise capacity using decimal prefixes, where each step is a multiple of 1000:

$$1\ KB = 1000\ bytes,\quad 1\ MB = 1000^2\ bytes,\quad 1\ GB = 1000^3\ bytes$$

Operating systems and memory specs, on the other hand, often report size using binary prefixes, where each step is a multiple of 1024 (the nearest power of 2):

$$1\ KiB = 1024\ bytes,\quad 1\ MiB = 1024^2\ bytes,\quad 1\ GiB = 1024^3\ bytes$$

This is exactly why a drive sold as "1 TB" shows up as roughly 931 GiB in your file explorer - the same number of bytes, described with two different rulers.

How the conversion works

Every unit is first converted to a common base of raw bytes, then from bytes into the target unit:

$$bytes = value \times factor_{from}, \qquad result = \frac{bytes}{factor_{to}}$$

where factor is 1/8 for bits, 1 for bytes, and a power of 1000 (decimal) or 1024 (binary) for every larger unit. This is the same technique used internally by operating systems and storage tools to reconcile the two numbering systems.

How to use this tool

1. Enter the numeric value you want to convert
2. Choose the unit you're converting from
3. Choose the unit you're converting to
4. Submit to see the converted value, plus a full table showing that same amount expressed in every supported unit - bits, bytes, decimal KB through PB, and binary KiB through PiB

Worked example

Converting 1 GB (decimal gigabyte) to MiB (binary mebibyte):

$$1\ GB = 1{,}000{,}000{,}000\ bytes, \qquad 1\ MiB = 1{,}048{,}576\ bytes$$ $$result = \frac{1{,}000{,}000{,}000}{1{,}048{,}576} \approx 953.674\ MiB$$

So 1 GB (as advertised on a storage label) is about 953.67 MiB - noticeably less than 1000 MiB, which is the gap people notice when a "1 TB" drive doesn't show a full 1000 GB of usable space in their operating system.