thousand, K (thousand)

As a general rule, thousand should be expressed either in words or in numbers.

• Felicity received five thousand dollars as a graduation present from her grandparents.
• In his very first job, Patel was making $75,000 a year.

The capital letter K is sometimes used informally to represent one thousand (dollars), especially in newspaper headlines. There is no space between the numeral and the letter K, as in 75K.

• Headline: Lottery winner gets 150K

The letter K should not be used as an abbreviation for one thousand (dollars) in formal writing.

• The grant amounted to $150,000 (not 150K).