Megabytes to Gigabytes Converter

MB to GB Quick Reference (Binary)

Binary vs Decimal: MiB/GiB vs MB/GB

There are two common ways to relate megabytes and gigabytes, and they give slightly different results. The binary convention treats 1 GB as 1,024 MB because computer memory is organized in powers of two (2¹⁰ = 1,024). The decimal convention treats 1 GB as 1,000 MB, following the standard SI prefixes where "giga" means exactly one billion.

To avoid ambiguity, the IEC introduced separate binary units: the mebibyte (MiB) = 1,024 KiB and the gibibyte (GiB) = 1,024 MiB. Under that standard, "MB" and "GB" are strictly decimal (powers of 1,000) while "MiB" and "GiB" are binary (powers of 1,024). In everyday use, however, "MB" and "GB" are often used loosely for both, which is why this converter lets you choose the base.

Why Storage Vendors Use Decimal

Manufacturers of hard drives, SSDs, USB flash drives, and SD cards label capacity using decimal units, where 1 GB = 1,000 MB and 1 TB = 1,000 GB. Operating systems such as Windows, on the other hand, traditionally report capacity using binary math (1 GB = 1,024 MB) while still labeling it "GB".

This mismatch is why a drive advertised as "1,000 GB" can appear as roughly "931 GB" in your operating system. No storage is missing — the same number of bytes is simply being divided by 1,024³ instead of 1,000³. Switching this converter between binary and decimal shows exactly how the two interpretations differ.

Common Uses

• File sizes: estimating how many photos, songs, or documents (each a few MB) fit within a GB-sized storage budget.
• Mobile data plans: converting a data allowance given in GB into the MB consumed by individual apps and downloads.
• Storage planning: comparing advertised drive capacity (decimal GB) with what your operating system reports (binary).
• Backups and transfers: checking whether a folder measured in MB will fit on a GB-sized drive or cloud allocation.

Related Calculators