GB vs GiB
Decimal Gigabytes and Binary Gibibytes
GB vs GiB is the difference between two ways of counting storage. A gigabyte (GB) is 1,000,000,000 bytes, a power of ten, and it is how drive manufacturers label capacity. A gibibyte (GiB) is 1,073,741,824 bytes, which is 2 to the power of 30. The name gibibyte is a binary unit, created so that it would not be confused with the decimal gigabyte.
The difference grows with size. A GiB is about 7 percent larger than a GB, and a tebibyte (TiB) is about 10 percent larger than a terabyte (TB). Both units are correct, but mixing them causes confusion when a drive's label and its reported size do not match.
Why a 1 TB Drive Shows About 931 GiB
Take a drive sold as 1 TB, which holds 1,000,000,000,000 bytes. An operating system that counts in powers of two divides that number by 1,073,741,824 and reports about 931 GiB. Nothing has been lost. The same bytes are simply expressed in a different unit. Many systems label the result GB even though the value is in GiB, which is a common source of confusion.
Formatting reduces usable space further. A file system stores its own metadata, and many Linux file systems reserve a small share of blocks for privileged processes. Ext4, for example, reserves about five percent by default. The usable size is therefore always somewhat smaller than the raw figure.
A Real-World Example With a 2 TB Server Drive
A server administrator installs a drive sold as 2 TB. The operating system reports roughly 1.82 TiB, which looks like missing space when set against the 2 TB label. The drive is intact. 2 TB is 2,000,000,000,000 bytes, and 1.82 TiB is the same number of bytes written in a binary unit. After formatting, the usable space is smaller again, so the final figure is lower still.
Frequently asked questions
Why does Windows show less space than the drive label?
Windows reports sizes in binary units but labels them with decimal names such as GB and TB. A drive sold as 1 TB therefore appears as about 931 GB. The drive still holds its full advertised capacity in decimal bytes. Formatting then reserves some of that space for file system structures, which lowers the usable total a little more.
Is a GiB bigger than a GB?
Yes. One GiB is 1,073,741,824 bytes, while one GB is 1,000,000,000 bytes, so a GiB is about 7 percent larger. Check which unit a product or tool uses before comparing storage numbers from different sources. Space needs for hosting are discussed in disk space hosting.