A21K

Billion

UK /["/ˈbɪljən/"]/US /["/ˈbɪljən/"]/

Definition

1 000 000 000; one thousand million

In simple words: One thousand million (1,000,000,000)

Examples

  • Worldwide sales reached 2.5 billion.
  • half a billion dollars
  • They have spent billions on the problem *(= billions of dollars, etc.)*.
  • Our immune systems are killing billions of germs right now.

Usage notes

Used in financial contexts and discussions about large quantities. It’s appropriate in both spoken and written communication. Avoid using it in very casual contexts.

Grammar pattern

standalone number

Memory hint

Think of 'billion' as 'big million' — a giant number!

Collocations

  • billion dollars
  • billion people
  • billion assets
  • billion views
  • spend a billion

Synonyms

  • thousand million
  • 10^9
  • giga

Antonyms

  • million
  • thousand

Common mistakes

  • Confused with 'million' – learners often mix up the scale of these numbers.
  • Mispronounced or misspoken as 'billon'.
  • Inaccurate usage in fiscal contexts, such as saying 'a billion of' instead of 'a billion dollars'.