MB to GB converter
Convert megabytes to gigabytes and see all other storage units at once. Toggle between decimal (SI) units where 1 GB = 1000 MB and binary (IEC) units where 1 GiB = 1024 MiB.
Decimal (SI): 1 KB = 1,000 B · 1 MB = 1,000,000 B · used by storage manufacturers
How it works
All unit conversions use pure JavaScript arithmetic. No library required. Decimal (SI) conversions divide by powers of 1000; binary (IEC) conversions divide by powers of 1024. Results update instantly as you type.
Processing runs in your browser
All calculations happen locally in the page. Our servers are not involved at any point.
Related operations
For converting between binary, hex, and decimal values, try the number base converter. To convert between length, mass, and other units, use the unit converter. For computing file hashes alongside size checks, see the hash generator.
Frequently asked questions
How many MB are in a GB?
In decimal (SI) units, 1 GB = 1000 MB. In binary (IEC) units, 1 GiB = 1024 MiB. Hard drive manufacturers use decimal, while operating systems often report sizes in binary units.
Why does my hard drive show less space than advertised?
Hard drive manufacturers use decimal units (1 GB = 1,000,000,000 bytes), while operating systems like Windows and macOS historically display sizes in binary units (1 GB = 1,073,741,824 bytes). A 1 TB drive shows as approximately 931 GiB in your OS.
What is the difference between MB and MiB?
MB (megabyte) in the SI standard = 1,000,000 bytes. MiB (mebibyte) in the IEC standard = 1,048,576 bytes (1024²). The IEC introduced the MiB/GiB/TiB prefixes to remove ambiguity, though MB is still commonly used for both.
Does this tool work offline?
Yes. The conversion runs entirely in your browser with no network requests. It works offline once the page is loaded.