πŸ”„
← Back to Blog

Data Storage Units: The Complete Guide to KB, MB, GB, TB, PB Conversion

Data storage units can be confusing because there are two different systems: the decimal (SI) system used by hard drive manufacturers, and the binary system used by operating systems. This discrepancy is why a "500 GB" hard drive shows up as approximately 465 GB on your computer.

Understanding Bits vs Bytes

  • A **bit** (b) is the smallest data unit, representing a single binary digit (0 or 1)
  • A **byte** (B) = 8 bits
  • Network speeds are measured in **bits per second** (Mbps, Gbps)
  • Storage is measured in **bytes** (GB, TB)

    • Binary vs Decimal Prefixes

    Decimal (SI) β€” Used by Drive Manufacturers

    1 kB = 1,000 bytes | 1 MB = 1,000,000 bytes | 1 GB = 1,000,000,000 bytes | 1 TB = 1,000,000,000,000 bytes

    Binary (IEC) β€” Used by Operating Systems

    1 KiB = 1,024 bytes | 1 MiB = 1,048,576 bytes | 1 GiB = 1,073,741,824 bytes | 1 TiB = 1,099,511,627,776 bytes

    Conversion Formulas

    Within Binary: 1 B = 8 b, 1 KiB = 1024 B, 1 MiB = 1024 KiB, 1 GiB = 1024 MiB, 1 TiB = 1024 GiB, 1 PiB = 1024 TiB

    Decimal→Binary Approximations:

  • 1 GB (decimal) β‰ˆ 0.931 GiB (binary)
  • 1 TB (decimal) β‰ˆ 0.909 TiB (binary)

    • Data Size Reference

    Practical Examples

    Why does my 1TB drive only show 931GB? A 1TB drive contains 1,000,000,000,000 bytes. Your OS divides by 1024Β³ (GiB), giving ~931 GiB. The space isn't "missing" β€” it's a measurement system difference.

    Internet Speeds: A 500 Mbps connection can theoretically download at 62.5 MB/s (divide by 8). Real-world speeds are lower due to overhead.

    Use our GB to MB Converter and Bytes to GB Converter for quick data conversions.

    Unit Size Example
    1 byte 8 bits One character
    1 KiB 1024 B Short email
    1 MiB 1024 KiB 3-min MP3 song
    1 GiB 1024 MiB HD movie (45 min)
    1 TiB 1024 GiB 250,000 songs
    1 PiB 1024 TiB 10 years of HD video

    Try the Converter

    GB to MBBytes to GB