Last updated: April 2026 · Reviewed by Calculatormatics Editorial Team

Data Storage Converter

A free data storage converter that handles every common unit from a single bit up to a petabyte, plus the IEC binary-prefixed units (KiB, MiB, GiB) that operating systems actually use. Enter a value in any unit and the calculator instantly returns the equivalent in every other unit. The tool uses the binary standard by default — 1 KB = 1,024 bytes, 1 MB = 1,048,576 bytes — which matches how Windows, macOS, and Linux report file and disk sizes. This is the source of the famous "missing space" issue: a 1 TB hard drive advertised by a manufacturer (using the decimal SI definition, 1 TB = 1,000,000,000,000 bytes) shows as roughly 931 GB in your operating system, because the OS measures TB as 2⁴⁰ = 1,099,511,627,776 bytes. The conversion table on this page makes the difference explicit so you can pick the correct interpretation for your context. Useful for sizing backups, estimating cloud storage costs, comparing drive specs, calculating bandwidth (network speeds use bits, file sizes use bytes — 1 byte = 8 bits), and working out how many files of a given size fit in a given capacity. Enter a value below to convert.

How Data Storage Units Work

Data is ultimately stored as bits — binary digits, each a 0 or a 1. Eight bits make one byte, which can represent 256 distinct values (2&sup8;). All larger units — kilobytes, megabytes, and so on — are defined as powers of either 1,000 (decimal/SI) or 1,024 (binary) bytes, and the choice between these two definitions causes the well-known confusion between advertised and reported storage sizes.

Binary vs. Decimal Definitions

There are two competing standards for defining storage units above the byte:

The IEC introduced the "binary prefix" names in 1998 to resolve this ambiguity: kibibyte (KiB), mebibyte (MiB), gibibyte (GiB), tebibyte (TiB). These always mean powers of 1,024. This converter uses the binary standard (1 KB = 1,024 bytes), which is how Windows, Linux, and macOS report file and partition sizes.

Data Storage Hierarchy

Network Speed vs. File Size

A common source of confusion: internet speeds are quoted in megabits per second (Mbps), while file sizes use megabytes (MB). Since 1 byte = 8 bits, a 100 Mbps connection downloads at 100 / 8 = 12.5 MB/s. For developers estimating AI API costs based on data volume, the LLM API Cost Calculator handles token-based pricing. For general percentage-based conversions, our Percentage Calculator can help.

Download speed (MB/s) = Connection speed (Mbps) ÷ 8

Worked Example: Convert 5 GB to MB (Binary)

In the binary (IEC) system used by operating systems, 1 GiB = 1024 MiB. In the decimal (SI) system used by most hardware marketing, 1 GB = 1000 MB. The conversion depends on which system you are using.

Binary (IEC): 1 GiB = 1024 MiB
  5 GiB × 1024 = 5,120 MiB

Decimal (SI):  1 GB = 1000 MB
  5 GB × 1000 = 5,000 MB

Difference:  5,120 − 5,000 = 120 MB (2.4%)

So 5 GB = 5,120 MB (binary) or 5,000 MB (decimal). This mismatch is why a "1 TB" hard drive shows as roughly 931 GiB in Windows — the drive is 1 × 10¹² bytes, but Windows reports in binary units.

Frequently Asked Questions