One gibibyte is exactly 1.073741824 gigabytes, since a gibibyte is 2³⁰ bytes and a gigabyte is exactly 10⁹ bytes. The 7.4 per cent gap between them is the arithmetic behind the most common support question in consumer computing.
About the units
The gibibyte was defined by the IEC in 1998 as 1,073,741,824 bytes, giving computing an unambiguous name for 2³⁰ bytes. Before that, GB meant one thing to a drive manufacturer and another to an operating system. The distinction is not pedantry at this scale: 7.4 per cent of a large drive is a significant quantity, and it is the entire explanation for why storage always appears smaller once installed. Windows reports binary values but labels them GB, which is the specific choice that keeps the confusion alive; Linux and macOS report decimal GB for storage and use GiB where they mean binary.
The exact factor
The exact value is 2³⁰ ÷ 10⁹ = 1,073,741,824 ÷ 1,000,000,000 = 1.073741824, which is 1.024³. Going the other way, a gigabyte is 0.931322574615479 gibibytes — the 0.93 that turns a 500 GB drive into 465 GB on screen. RAM is the counter-case: memory modules are genuinely binary, so 8 GB of RAM means 8 GiB, and here the decimal label is the incorrect one.
Where you meet this conversion
Cloud instance sizing, where memory is allocated in GiB and billed by the hour, so misreading the unit means paying for capacity you did not intend. Virtual machine and container limits, database buffer pools and JVM heap sizes are all specified in binary units. On the consumer side it explains every discrepancy between a box and a properties dialog. Storage array and NAS documentation usually states which convention it uses precisely because the difference is large enough to matter in a purchase decision.