As in a number of the smallest de facto units of anything you can have in the universe?

Currently in the running in my mind:

  • Quanta
  • Quantums

2 Answers 2


Merriam-Webster, Wiktionary, The American Heritage Dictionary of the English Language, and the Collins English Dictionary all list only quanta as the plural form. So if I wanted to be on the safe side, I'd recommend that over quantums. The usage stats from the British National Corpus and the Corpus of Contemporary American English look as follows:

         BNC   COCA

quanta    35     95
quantums   0      3

Google results are too skewed to be included, as Quanta seems to be a popular proper name.

  • 2
    Quantum is a derivation from Latin, and thus takes the Latin pluralisation. Quantum->Quanta like Forum->Fora and so forth.
    – Carmi
    Jan 27, 2011 at 18:02

'Quanta' is usually used, but 'quantums' is also valid according to the Oxford English Dictionary.

  • 2
    In physics, quanta would be the usual plural. However, students also use Quantum also to mean their class on Quantum Mechanics, and if you somehow needed to pluralize that (I don't see how that would happen), the plural would be Quantums. May 9, 2011 at 2:57
  • 1
    Wow, @Peter Shor, straight from the horse's mouth. :)
    – senderle
    Jul 25, 2011 at 16:15

Not the answer you're looking for? Browse other questions tagged or ask your own question.