1000 vs 1024: Decimal and Binary Storage Units

Is 1 GB 1000 or 1024 MB?

By standard definitions, 1,000 MB = 1 GB and 1,024 MiB = 1 GiB. MB and GB are decimal units; MiB and GiB are binary units.

Some apps use the familiar labels “MB” and “GB” for binary quantities. In this converter, an unmarked “MB” input in the binary result (1,024-based) is read as MiB, and the result is shown as GiB. Some apps may display that GiB value as “GB”. The decimal result (1,000-based) uses the standard MB and GB definitions.

Standard symbols make the difference explicit

Decimal SI prefixes scale by 1,000: kilo, mega and giga. Binary IEC prefixes scale by 1,024: kibi, mebi and gibi. The different names and symbols identify the byte factor used. See the NIST SI prefix definitions and IEC unit-symbol guidance.

What does 1024 mean?

1024 is 2 to the power of 10. Powers of two are useful for describing binary quantities. SI prefixes keep their decimal definitions; the binary prefixes give powers of two their own names.

1024 MB = 1.024 GB. This decimal input represents 1,024,000,000 bytes.

1024 MiB = 1 GiB. This binary input represents 1,073,741,824 bytes.

These are two different capacities. To compare the same capacity across standards, convert through bytes: 1024 MB = 0.95367431640625 GiB.

Four ways to interpret 1024

The source definition and the target unit are separate choices. The same input number can describe different capacities.

Choose the right interpretation in three steps

1. Check the unit definition used by the source app or label.
2. Distinguish decimal MB from binary MiB.
3. If you know the exact byte count, choose B as the source unit and convert from there.

The first and third rows share one byte amount; the second and fourth share another. These are two capacities, each expressed in two ways.

Keep the same capacity when comparing units

The two ordinary results apply their respective definitions to the familiar input label. For input 1024, the decimal result (1,000-based) is 1.024 GB because its source is decimal MB; the binary result (1,024-based) reads that label as MiB.

To express the original 1,073,741,824 bytes in decimal GB, use the explicit MiB to GB example above. It gives 1.073741824 GB while preserving the source byte amount.

These table values are exact. The converter marks a rounded main result with ≈ and keeps its full exact value in Calculation details.

Why do some tools say 1024 MB = 1 GB?

They may be displaying binary quantities with familiar labels. Here, the input label “MB” is read as MiB for the binary result (1,024-based), so the standards-based answer is 1,024 MiB = 1 GiB; some apps label GiB as “GB”. Check the software’s unit definition before comparing its number with a product label.

For the exact definitions and a same-capacity comparison, see GB vs GiB. The data size reference lists every supported byte factor.

Use the matching converter

Convert MB to GB or convert GB to MB and see both 1024-based and 1000-based results. For a same-capacity comparison, use GB to GiB with explicit units.