English language numerals

See also List of numbers (to be merged)

There are two main English language systems of number names: the American system (also used in Canada) and the European system (used in most Germanic and Romance languages). The European system is the older one and is also called the British system, because it was used in Great Britain at one point. Britain and Australia have recently largely switched to the American system. The American system was originally invented by the French, adopted by the United States, and then abandoned by France.

The principal difference between the two systems is the meaning of the word "billion" and its multiples: in the European system a billion is a million million (10¹²), a trillion is a million billion (10¹⁸), and so forth; a thousand million (10⁹) is called a milliard, a thousand billion (10¹⁵) a billiard[?] etc. In the American system a billion is a thousand million (10⁹), a trillion is a thousand billion (10¹²), and so forth. See more below.

• Zero (nought, nowt, oh, nil)
• One
• Two (pair, brace)
• Three
• Four
• Five
• Six
• Seven
• Eight
• Nine
• Ten
• Eleven
• Twelve (dozen)
• Thirteen
• Fourteen
• Fifteen
• Sixteen
• Seventeen
• Eighteen
• Nineteen
• Twenty ( score)
• Thirty[?]
• Forty[?]
• Fifty[?]
• Sixty[?]
• Seventy[?]
• Eighty[?]
• Ninety[?]
• Hundred
• Gross (144 or a dozen dozen)
• Thousand
• Myriad (10,000)
• Million
• Milliard (1000 million)
• Billion
• Trillion
• Quadrillion
• Quintillion
• Sextillion
• Septillion
• Octillion
• Nonilllion
• Decillion
• Undecillion
• Duodecillion
• Tredecillion
• Quattuordecillion
• Quindecillion
• Sexdecillion
• Septendecillion
• Octodecillion
• Novemdecillion
• Vigintillion
• Googol
• Centillion
• Googolplex

After the million mark, the European number system is based on millions, the American number system is based on thousands. The prefix of the number name corresponds to the power of the base number. e.g. bi means 2, tri means 3, quadri means 4, etc.

In the European system, each number is a power of a million, i.e. (n)illion = (one million)ⁿ = 10^n×6.
one billion = (one million)² or 10¹²;
one trillion = (one million)³ or 10¹⁸;
one quadrillion = (one million)⁴ or 10²⁴;
one quintillion = (one million)⁵ or 10³⁰;
one sextillion = (one million)⁶ or 10³⁶;
one septillion = (one million)⁷ or 10⁴²;
one octillion = (one million)⁸ or 10⁴⁸;
one nonillion = (one million)⁹ or 10⁵⁴;
one decillion = (one million)¹⁰ or 10⁶⁰;
one undecillion = (one million)¹¹ or 10⁶⁶;
one duodecillion = (one million)¹² or 10⁷²;
one tredecillion = (one million)¹³ or 10⁷⁸;
one quattuordecillion = (one million)¹⁴ or 10⁸⁴;
one quindecillion = (one million)¹⁵ or 10⁹⁰;
one sexdecillion = (one million)¹⁶ or 10⁹⁶;
one septendecillion = (one million)¹⁷ or 10¹⁰²;
one octodecillion = (one million)¹⁸ or 10¹⁰⁸;
one novemdecillion = (one million)¹⁹ or 10¹¹⁴;
one vigintillion = (one million)²⁰ or 10¹²⁰;
...
one centillion = (one million)¹⁰⁰ or 10 ⁶⁰⁰.

In the American system, each number is a power of a thousand (the prefix and the number of power will match only when the first 1000 is factored out), i.e. (n)illion = 1000 × 1000ⁿ or 10^(n+1)×3.

one billion = 1000 * 1000² or 10⁹;
one trillion = 1000 * 1000³ or 10¹²;
one quadrillion = 1000 * 1000⁴ or 10¹⁵;
one quintillion = 1000 * 1000⁵ or 10¹⁸;
one sextillion = 1000 * 1000⁶ or 10²¹;
one septillion = 1000 * 1000⁷ or 10²⁴;
one octillion = 1000 * 1000⁸ or 10²⁷;
one nonillion = 1000 * 1000⁹ or 10³⁰;
one decillion = 1000 * 1000¹⁰ or 10³³;
one undecillion = 1000 * 1000¹¹ or 10³⁶;
one duodecillion = 1000 * 1000¹² or 10³⁹;
one tredecillion = 1000 * 1000¹³ or 10⁴²;
one quattuordecillion = 1000 * 1000¹⁴ or 10⁴⁵;
one quindecillion = 1000 * 1000¹⁵ or 10⁴⁸;
one sexdecillion = 1000 * 1000¹⁶ or 10⁵¹;
one septendecillion = 1000 * 1000¹⁷ or 10⁵⁴;
one octodecillion = 1000 * 1000¹⁸ or 10⁵⁷;
one novemdecillion = 1000 * 1000¹⁹ or 10⁶⁰;
one vigintillion = 1000 * 1000²⁰ or 10⁶³;
...
one centillion = 1000 * 1000¹⁰⁰ or 10 ³⁰³.

For more information on prefixes, see SI prefix. See also Cardinal number and Natural number

NOTE: Most of these number names are not used in ordinary writing. The "-illion"s above "quintillion" are almost nowhere to be seen, except perhaps in lists of number names such as this one. Larger numbers are referred to as powers of ten using scientific notation, for instance, as "10²⁵" (read "ten to the twenty-fifth"), etc. "Googol", however, is not uncommonly used for rough approximations.

---

Note that Indian English additionally uses the word crore to denote ten million, originally as a unit of value e.g. ten crore Rupees (see Kaun Banega Crorepati, the Indian version of Who Wants To Be A Millionaire?). Example: Faced with the worst drought conditions in three decades, the Andhra Pradesh government has asked for an assistance of Rs 2160 crore from the central government...

---

Umpteen is used to mean a large number. Usually it refers to the number of times something has happened, rather than a number of objects. Usually however the number referred to is less than a hundred.

Zillion and gazillion are fictitious very large numbers. The terms 'a (ga)zillion' and '(ga)zillions' are used informally, meaning very many, as in the Zillions of Games software product.

---

See How to name numbers in English