Backblaze on how OS X displays file sizes:

Starting with Mac OS X 10.6, Apple calculates disk storage using decimal (base 10) math:

  • 1 KB is 1,000 bytes
  • 1 MB is 1,000,000 bytes or 1,000 KB
  • 1 GB is 1,000,000,000 bytes or 1,000 MB

Backblaze’s restore browser, Windows, and Mac OS X 10.5 and earlier all use binary (base 2) math:

  • 1 KB is 1,024 bytes
  • 1 MB is 1,048,576 bytes or 1,024 KB
  • 1 GB is 1,073,741,824 bytes or 1,024 MB

Why on Earth would they use base 10?

π