Megabytes to Gigabytes Converter

About the mb to gb calculation

One megabyte is exactly 0.001 gigabytes, so converting between them is a single multiplication. Enter any value above and the result updates as you type. Decimal megabyte — 1,000,000 bytes, the definition storage manufacturers use. Decimal gigabyte. This is why a "1 TB" drive shows as roughly 931 GB in your operating system.

Formula

GB = MB × 0.001

1 MB = 0.001 GB
1 GB = 1,000 MB

Worked example

To convert 500 MB, multiply by 0.001: 500 × 0.001 = 0.5 GB.

Frequently asked questions

How many gigabytes are in a megabyte?

There are 0.001 gigabytes in one megabyte. To convert any amount, multiply the number of megabytes by 0.001.

How do I convert gigabytes back to megabytes?

Divide instead of multiplying, or equivalently multiply by 1,000. One gigabyte is 1,000 megabytes.

Is this conversion exact?

Yes, provided both sides use the same convention. Decimal units (KB, MB, GB) are powers of 1,000 and binary units (KiB, MiB, GiB) are powers of 1,024. Both are exact — the confusion comes from software labelling binary values with decimal names.

Is there anything that catches people out here?

Decimal units, where 1,000 MB = 1 GB. If your operating system disagrees, it is using binary units — see the GiB and MiB converters.

Sources

• IEC 80000-13 — binary and decimal prefixes for information units