Gibibytes to mebibytes (GiB to MiB)

One gibibyte is exactly 1,024 mebibytes. That is the definition of the prefixes, not a measurement: the decimal SI prefixes (kilo, mega, giga, tera) step by exactly 1,000, and the binary IEC prefixes (kibi, mebi, gibi, tebi) step by exactly 1,024. The two families are both exact; the trouble is only that software and storage labels do not always say which one they mean.

Worked through: 4 GiB x 1,024 = 4,096 MiB.

Going the other way, one mebibyte is 0.0009765625 gibibytes.

For mental arithmetic: Multiply by 1,024. 2 GiB is 2,048 MiB and 8 GiB is 8,192 MiB.

Exactly 1,024 MiB to the GiB, because both units are powers of two. The usual reason to go this way is a setting that only accepts mebibytes: a virtual machine's memory field, a swap file size or a JVM flag. 4 GiB is 4,096 MiB, not 4,000, and entering 4,000 gives a machine 2.3% less memory than intended. Kubernetes reads 4Gi and 4096Mi as the same amount, but 4G as 4,000,000,000 bytes, which is 3,815 MiB.

Precision is worth matching to the input. A measurement given as 0.5 GiB carries one or two significant figures, and reporting its conversion to six implies a precision the original never had.