Engineering principle: storage capacity, performance and resilience are separate design dimensions. Size all three for the workload rather than relying on a single headline specification.
Overview
Storage manufacturers normally quote decimal units: 1 TB is 1,000,000,000,000 bytes. IEC binary units use powers of 1024: 1 TiB is 1,099,511,627,776 bytes.
Engineering considerations
Therefore 16 TB is approximately 14.55 TiB. The bytes have not disappeared; the labels use different unit systems. Filesystem formatting, metadata and reserved areas can make the displayed usable figure smaller still.
How to plan it
When comparing storage specifications, keep units explicit. A vendor quote in TB should not be compared directly with an operating-system value in TiB without conversion.
Design implications
The TB ↔ TiB Converter provides the arithmetic for common decimal and binary storage units.