The Origin of the Confusion
When you buy a 1 Terabyte (1 TB) external hard drive or SSD and plug it into a Windows computer, the operating system reports the capacity as approximately 931 GB. The drive is not defective or missing storageโthe discrepancy comes from two competing definitions of "Kilo", "Mega", and "Giga".
SI Decimal (1000) vs IEC Binary (1024)
1
Decimal (SI Standard - Used by Hard Drive Manufacturers):
2
Binary (IEC Standard - Used by Computing Architectures & Windows):
Why 1 TB = 931.32 GiB
To find the true binary capacity of a 1,000,000,000,000 Byte drive:
Mathematical Equation
Capacity in GiB = (1,000,000,000,000 / 1,073,741,824) โ 931.3225746 GiB
Windows labels this value as "GB" instead of the formally correct "GiB", causing millions of users to assume storage was lost. macOS and modern Linux distributions have aligned with SI standards and report 1.00 TB directly.
