How to convert MB to GB
GB = MB × 0.001. The scale factor is the source-unit factor divided by the destination-unit factor.
Worked example
A 1,500 MB file converts to 1.5 GB.
- Start with 1,500 MB.
- Multiply 1,500 by 0.001.
- Report 1.5 GB, rounded to the precision of your original measurement.
This is a decimal conversion: divide by 1000. If your application reports MiB rather than MB, select the MiB converter instead.
Check the reverse conversion
1 GB = 1,000 MB. Use the gigabyte to megabyte converter to calculate in the opposite direction. This has its own formula and reference table.
Definitions that matter
A byte is eight bits. MB is not MiB, and GB is not GiB. Storage capacities are quantities; data-transfer rates such as Mbps add a time dimension and are not included here.
The base unit for this category is B. One MB corresponds to 1,000,000 byte; one GB corresponds to 1,000,000,000 byte. These definitions explain the relationship rather than relying on a rounded display value.
Sources and precision
Definitions: NIST binary prefixes. Calculations use double precision; the tool defaults to a readable rounded result, while tables show up to ten significant digits. Displaying more digits does not increase the accuracy of the original measurement.
Read our calculation methodology and content standards, or continue with decimal versus binary storage prefixes.