The numeral trillion refers to one of two number values, depending on the context of where and how it is being used. It is the largest numerical value in everyday non-scientific use in the English language. It comes between a billion and a quadrillion.

Usage

Short scale usage

In the short scale used in Brazil, Russia, Turkey, Greece, Puerto Rico and most English-speaking countries, a trillion is 10¹² or 1 000 000 000 000 (a one followed by twelve zeros) or thousand billions (short scale usage). It is one million million or (1 million)² or one thousandth of a quadrillion (short scale usage). The SI prefix for this number is tera.

While the United Kingdom, Ireland, Australia and New Zealand traditionally employed the long scale usage, some years ago they largely switched to the short scale usage of 10¹².

Long scale usage

In the long scale used in other countries and languages, a trillion (or its translated equivalent) is 10¹⁸ or 1 000 000 000 000 000 000 (a one followed by eighteen zeros), a million billions (long scale usage). It is one million million million or (1 million)³ or one millionth of a quadrillion (long scale usage). The SI prefix for this number is exa.

History

The history of trillion is described in the Long scale article.

Ambiguity

For reasons of the ambiguity described above, some avoid the usage of the term trillion and instead use the corresponding millions (million million and million million million) or powers of ten (10^12 and 10^18) or SI prefixes (tera- and exa-) as appropriate.

However, some people use the word trillion to mean an unspecified large number. Then it falls into the same category as umpteen and zillion.

See also

• List of numbers
• Names of large numbers