SI vs. Binary Prefixes

There are two conventions: SI (decimal) — 1 KB = 1,000 bytes — used by hard-drive manufacturers and network speeds. Binary (IEC) — 1 KiB = 1,024 bytes — used by operating systems. This discrepancy is why a "1 TB" hard drive shows as ~931 GiB in Windows. This converter supports both systems.

Common Conversions

  • 1 byte = 8 bits
  • 1 KB = 1,000 bytes (SI) / 1,024 bytes (binary)
  • 1 MB = 1,000 KB = 1,000,000 bytes
  • 1 GB = 1,000 MB = 10⁹ bytes
  • 1 TB = 1,000 GB = 10¹² bytes
  • 1 GiB = 1,024 MiB = 1,073,741,824 bytes

Real-World Sizes

  • Plain text email ≈ 10–50 KB
  • MP3 song ≈ 3–5 MB
  • Full HD movie ≈ 4–8 GB
  • 4K movie ≈ 50–100 GB
  • Smartphone photo ≈ 3–10 MB
  • Human genome ≈ ~1.5 GB compressed