How this calculator works
The megabyte and gigabyte are decimal multiples of the byte: 1 MB is 1,000,000 bytes and 1 GB is 1,000,000,000 bytes. The IEC binary prefixes mebibyte and gibibyte are powers of 1,024: 1 MiB is 1,048,576 bytes and 1 GiB is 1,073,741,824 bytes. Because 1,024 is not 1,000, a value in GB is always larger than the same value in GiB, and a storage capacity quoted in decimal gigabytes looks smaller when the same bytes are divided by 1,024 and labelled GiB.
Formula
gigabytes (decimal) = megabytes / 1,000. gibibytes (binary) = megabytes x 1,000,000 / 1,073,741,824 = megabytes / 1,073.741824. In the other direction, 1 GB = 1,000 MB and 1 GiB = 1,024 MiB.
Worked example
1,000 MB is exactly 1 GB and 0.931323 GiB. 2,000 MB is 2 GB and 1.86265 GiB. A 500,000 MB drive is 500 GB or 465.661 GiB, which is the reason a drive advertised as 500 GB can show about 466 GB in software that uses binary divisions.
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Frequently asked questions
Why do two programs show different GB values for the same drive?
They divide the same byte count by different numbers and may label both results GB. A decimal division uses 1,000,000,000 bytes per GB while a binary division uses 1,073,741,824 bytes per GiB. The binary result is smaller, which is why the displayed capacity changes.
Is GB bigger than GiB?
Yes. One gigabyte is 1,000,000,000 bytes and one gibibyte is 1,073,741,824 bytes, so 1 GiB is about 1.07374 GB.
Does this page convert bits as well?
No. It stays with bytes and byte multiples. The Mbps calculator covers bit rates and the byte converter covers bits per byte.