Data Storage Units Explained: SI vs IEC

Introduction

Data storage units come in two main systems: SI (decimal) and IEC (binary). Understanding the difference is crucial for accurate data size representation and conversion.

SI Units (Decimal)

  • Based on powers of 1000.
  • Commonly used in storage device marketing (e.g., hard drives, SSDs).
  • Examples:
    • 1 Kilobyte (KB) = 1000 bytes
    • 1 Megabyte (MB) = 1,000,000 bytes
    • 1 Gigabyte (GB) = 1,000,000,000 bytes

IEC Units (Binary)

  • Based on powers of 1024.
  • Used in operating systems and software.
  • Examples:
    • 1 Kibibyte (KiB) = 1024 bytes
    • 1 Mebibyte (MiB) = 1,048,576 bytes
    • 1 Gibibyte (GiB) = 1,073,741,824 bytes

Why the Difference Matters

  • Storage manufacturers use SI units, while OS uses IEC units, causing confusion.
  • A “500 GB” hard drive may show less capacity in your OS due to this difference.
  • Accurate conversions require knowing which unit system is used.

How to Convert Between SI and IEC

  • Multiply or divide by powers of 1000 or 1024 accordingly.
  • Use tools like the Data Storage Converter for precise conversions.

Understand your data sizes better with knowledge of SI and IEC units!

Use Data Storage Converter