Spell out figures for cheques, contracts and invoices. Decimals become point four five, and a negative is labelled rather than left as a stray minus.
On a cheque, the amount in words is the one that counts. Where the figures and the words disagree, the words govern. This is codified, for example in the Uniform Commercial Code in the United States and in equivalent bills of exchange legislation elsewhere.
The reason is tampering. Digits are trivially altered: a 1 becomes a 4, a 7 becomes a 9, and a zero appended multiplies the amount tenfold. A written phrase resists all of that, because inserting a plausible word into an existing line of handwriting is far harder than closing a loop.
The same logic drives the convention in contracts, where quantities and sums are routinely given twice (*five thousand (5,000) units*) so that a typographical error in one form is caught by the other. Some jurisdictions require the written form on invoices outright.
Beyond the legal cases, spelling a figure out removes ambiguity that formatting introduces. Whether `1,000` means one thousand or one depends entirely on whether the reader uses the comma as a thousands separator or a decimal point, and that split runs straight through Europe.
A billion is not a fixed quantity. On the short scale it is a thousand million, 10^9. On the long scale it is a million million, 10^12. A thousand times larger.
The short scale is used in English today, including in British English, which switched officially in 1974 when the government adopted it for statistics. The long scale remains standard in much of continental Europe, in Spanish and Portuguese-speaking countries, and in older British writing. A French *billion* is 10^12, and their word for 10^9 is *milliard*.
This tool uses the short scale: thousand, million, billion, trillion, quadrillion. That is right for English output and is worth knowing if the figure is going to a reader whose first language uses the other convention, because the discrepancy is silent. Both parties read a correct-looking word and understand different amounts.
It is also why *milliard* still appears in English writing from before the 1970s, and why financial documents crossing borders often give the digits alongside the words.
British English inserts *and* before the final component below a hundred: one hundred and twenty-three. American English usually omits it: one hundred twenty-three.
Neither is an error, and the American preference has a practical root, in cheque writing, *and* conventionally marks the decimal point, so *one hundred and fifty* could be read as 100.50 rather than 150. American cheque style writes *One hundred fifty and 00/100*, reserving *and* for the fractional part.
This tool follows British usage and includes *and*, which is correct for most English-speaking readers outside North America. It is worth being aware of if the output is going onto a US cheque, where the convention differs and the fractional form is expected.
Hyphenation is more settled: compound numbers from twenty-one to ninety-nine take a hyphen, and everything else does not. Forty-seven is hyphenated; four hundred is not; four hundred and forty-seven hyphenates only the final pair.
Decimals are read digit by digit after the word point: 89.5 becomes eighty-nine point five, and 0.25 becomes zero point two five rather than twenty-five hundredths. That is how amounts are spoken and it avoids the ambiguity of fraction wording.
Negative numbers get an explicit word rather than being left to a minus sign, which is easy to lose in a copy, a fax or a line break. A figure that reads *32* when it should read *-32* is a serious error and a leading hyphen is a fragile way to prevent it.
Large values are handled as arbitrary-precision integers rather than floating-point numbers. This matters more than it sounds: JavaScript's ordinary number type loses integer precision above 2^53, so 9007199254740993 silently becomes 9007199254740992 in a naive implementation, and the words that come out are wrong in the final digit. Converting the digit string directly avoids that entirely.
A column of figures can be pasted in whole, one per line, and each is converted independently.
Writing *twenty five* without the hyphen. Correct is twenty-five; the unhyphenated form is a common error on cheques and looks careless on a legal document.
Omitting *zero* before a decimal point. *Point five* is ambiguous in a way *zero point five* is not, and on a financial document the leading zero is a safeguard rather than a stylistic choice.
Mixing the scales, usually by translating *milliard* to *billion* or vice versa. If a figure has crossed a language boundary, verify which scale the source used before trusting the word.
And on cheques specifically: leaving space after the written amount, which allows words to be added. The convention is to draw a line through any remaining space so the amount cannot be extended.
The capitalisation toggle controls whether each result starts with a capital. Sentence position usually wants it; a figure embedded mid-sentence in a contract usually does not.
For cheques, remember the tool gives you the number in words and not the full conventional line. Most cheque formats expect the amount followed by *only*, or the American *and 00/100* form for the fractional part, and expect the remaining space to be ruled through.
For accessibility work, the written form is sometimes preferable in the text itself: screen readers handle plain digits well, but reading long strings of digits aloud is slow and the written form can be clearer in a heading or a summary line. That is a judgement call rather than a rule, and doing both, digits with words in parentheses, is often best.
This converts cardinal numbers. The counting words. It does not produce ordinals, the position words: first, second, third, twenty-first. Those follow their own pattern, mostly the cardinal plus *th*, with the irregular first, second and third, and the spelling shifts of fifth, eighth, ninth and twelfth. Compound ordinals only inflect the final element: twenty-first, not twentieth-first.
It also does not produce fractions. A half, a quarter and a third are irregular; beyond them, fractions use the ordinal as the denominator (three fifths, seven twelfths) and pluralise it when the numerator is greater than one. Decimals are handled instead, read digit by digit, which is the form financial and technical writing actually wants.
Years are a further special case worth knowing: 1984 is normally spoken as nineteen eighty-four rather than one thousand nine hundred and eighty-four, and 2008 as two thousand and eight. The convention shifts around the turn of a century and no single rule covers it, which is precisely why this tool converts the number rather than guessing that it is a year.
If you need any of these forms, convert the cardinal here and adjust the ending by hand. It is a small edit and more reliable than a rule that guesses wrong on the irregulars.
Digit by digit after the word point, so 89.5 becomes eighty-nine point five. That matches how amounts are spoken and avoids the ambiguity of fraction wording.
Because they legally govern where they disagree with the figures. Digits are easy to alter (a 1 into a 4, an appended zero) and a written phrase is far harder to tamper with convincingly.
No. That is the short scale, standard in English today. The long scale, still used in much of continental Europe, makes a billion a million million, a thousand times larger.
British English does: one hundred and twenty-three. American English usually omits it, partly because on cheques *and* conventionally marks the decimal part.
No. The digits are handled as arbitrary-precision integers, not floating point, so values above 2^53 keep their final digits exactly instead of being silently rounded.
Yes. Put one number per line and each is converted independently, so a spreadsheet column can be pasted straight in.
Compound numbers from twenty-one to ninety-nine take one. Hundreds, thousands and the rest do not, so four hundred and forty-seven hyphenates only the final pair.
No, only cardinal counting words. Ordinals have irregular forms (first, second, third, fifth, eighth, ninth, twelfth) so convert the cardinal here and adjust the ending yourself.