Storage Capacities:  The Numbers

• Hard drive manufacturers use storage capacaties in the multiples of ten below. 
  • By 1 GB, a manufacturer means 1,000,000,000 (10⁹) bytes.
• Windows and Mac OS, however, report multiples of two when measuring disk or RAM capacity
  • By 1 GB, Windows means 1,073,741,824 (2³⁰) bytes.  
• But see the new Binary Prefixes from NIST!

Adapted and revised from a table by Harry Phillips; used with permission.

For a full list of prefixes: 

• SI Prefixes (French Système International d'unités) from the National Institute of Standards and Technology (NIST)

New Binary Prefixes from NIST