What does quadrillion mean?
A quadrillion is the number 1,000,000,000,000,000, or 10^15. It is one thousand times a trillion and one million times a billion. In British and American English, it follows the short scale, in which the names of large numbers increase by factors of one thousand; some continental European long-scale traditions use the same word for 10^18, so international contexts may need clarification. The word is especially useful for discussing enormous financial sums, quantities of information, or measurements. Because such figures can be difficult to conceptualize, speakers may also express them through comparisons or scientific notation. Although the term sounds technical, it is an ordinary English number word rather than a specialist expression, and its dramatic size gives it a memorable place in public discussion.
nounThe number one thousand trillion, equal to 10^15. In the short scale used in Britain and the United States, it is written as 1,000,000,000,000,000.
- A cardinal number equal to one thousand trillion (10^15), especially when used to state an extremely large quantity.
"The project is expected to cost nearly a quadrillion dollars over the next century."
"The laboratory processed a quadrillion data points during the simulation."
"She estimated that completing the restoration would require a quadrillion dollars."
Use quadrillions for multiple units of 10^15 in the short scale; when referring to the individual place-value units, one quadrillion is composed of a thousand trillions.
"The observatory has recorded quadrillions of observations across its instruments."
A quadrillion has fifteen zeroes, making it large enough to describe both the scale of the universe and the scale of a national budget.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does quadrillion come from?
Quadrillion was formed in the 17th century through French quadrillion, from Latin quadrillion, a large multiple of a million. Its element quadr- derives from Latin quadratus, meaning “square,” via the place-name sequence through which the number was developed. The same root appears in English words such as quadratic, quadrangle, and quadrature, all referring to squares or four-part arrangements.
Related word forms
How quadrillion is actually used
In British and American usage, quadrillion follows the short scale and denotes 10^15. The word is primarily used in contexts involving very large amounts, although it can be used hyperbolically for an immense number or quantity.
Easily confused with quadrillion
A quadrillion is 10^15, while a quintillion is 10^18, a thousand times larger in the short scale used in Britain and the United States.