quadrillion

American  

[kwo-dril-yuhn] / kwɒˈdrɪl jən /

noun

quadrillions, plural quadrillion plural

1. a cardinal number represented in the U.S. by 1 followed by 15 zeros, and in Great Britain by 1 followed by 24 zeros.

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adjective

1. amounting to one quadrillion in number.

quadrillion British  

/ kwɒˈdrɪljən /

noun

1. US and Canadian word: septillion.  (in Britain) the number represented as one followed by 24 zeros (10 ²⁴ )

2. (in the US and Canada) the number represented as one followed by 15 zeros (10 ¹⁵ )

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determiner

1. 1. amounting to this number

      a quadrillion atoms

   2. ( as pronoun )

      a quadrillion

Other Word Forms

Derived Forms

• quadrillionth
  noun
• quadrillionth
  adjective

Inflected Forms

Nouns

• quadrillion
  plural
• quadrillions
  plural

Etymology

Origin of quadrillion

1665–75; quadr- + -illion (as in million )

Explanation

It's a little time consuming to write out the number one quadrillion, since it's a one and fifteen zeros. It's probably a good time to brush up on big numbers, now that billions and even trillions are bandied about as if they were mere dozens. A quadrillion is one followed by fifteen zeroes. If you're looking for a mnemonic, the root word, quad, "four" from the Latin quadri, refers to the number of groups of three zeroes that follow one thousand.

Example Sentences

See Examples For:

quadrillion quadrillions

That would take SpaceX’s market cap into the quadrillion territory, or 15 times global GDP.

From Barron's ● Jun. 2, 2026

Every operation -- such as applying a quantum gate -- influences more than 2 quadrillion complex numerical values, a "2" with 15 zeros.

From Science Daily ● May 11, 2026

But she had to take a second look when handed her receipt at 200 Degrees in Nottingham, which appeared to show she had a remaining balance of more than £63 quadrillion.

From BBC ● Feb. 21, 2026

He noted Google’s announcement that it had processed 1.3 quadrillion monthly tokens in October, up from 480 trillion in April.

From MarketWatch ● Nov. 4, 2025

So we skip the pancakes with all the cooking and measuring, and jump to the eating—by the way, sausage sandwiches are always a quadrillion times better than TV dinners, that's for sure.

From "Sunny" by Jason Reynolds

Its systems process literally quadrillions of trades each year.

From Barron's ● Jun. 4, 2026

This major accomplishment was enabled by Supercomputer Fugaku, Japan's premier high-performance system capable of performing quadrillions of calculations per second.

From Science Daily ● Nov. 18, 2025

Estimates for the value of all this vary wildly, from billions to quadrillions.

From BBC ● Jun. 8, 2024

Easily hundreds of trillions, maybe quadrillions, Cooley said.

From Seattle Times ● Apr. 1, 2024

She attempts the numeration-table, flounders somewhere in the quadrillions, and forgets where she left off.

From Men, Women, and Ghosts by Phelps, Elizabeth Stuart