Decimal vs binary
Decimal (SI): 1 kB = 1000 bytes, 1 MB = 1 000 000 bytes — used by drive manufacturers and most networking specs. Binary (IEC): 1 KiB = 1024 bytes, 1 MiB = 1 048 576 bytes — used by Windows, Linux file managers and RAM measurements. The difference grows with each prefix: a "1 TB" hard drive holds about 0.909 TiB.
Common values
- 1 byte = 8 bits
- 1 KB = 1000 B, 1 KiB = 1024 B
- 1 GB = 8 × 10⁹ bits = 1000 MB
- 1 TB ≈ 0.909 TiB
FAQ
Why does my "500 GB" SSD show as 465 GB?
Because Windows reports in GiB (binary) but labels them "GB". 500 × 10⁹ bytes ÷ 1024³ ≈ 465.66 GiB.