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.

---

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 )

---

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

The two companies could be planning to spend around a combined 2 quadrillion won over the next decade, nearly double Morningstar’s capex estimates.

From The Wall Street Journal ● Jun. 29, 2026

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

She added she would have preferred to have a £63 quadrillion gift card to spend at the supermarket.

From BBC ● Feb. 21, 2026

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

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

From BBC ● Jun. 8, 2024

With Leonardo's massive computing power, allowing quadrillions of calculations per second, they could simulate a wide range of water flow speeds and conditions.

From Science Daily ● May 17, 2024

Easily hundreds of trillions, maybe quadrillions, Cooley said.

From Seattle Times ● Apr. 1, 2024

All of us will be there, and the thousands, and millions, and billions, and trillions, and quadrillions that have died will be there.

From Lectures of Col. R. G. Ingersoll - Latest by Ingersoll, Robert Green