Number to Words Converter: British and American

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How to use this tool

Type a number and read the words. The style selector switches between British and American conventions, and the capitalisation selector covers the four cases you are likely to need, including the sentence case that banks and contracts usually want.

The green box gives the line you would actually write on a cheque, which is not quite the same as the plain words. Pence and cents go in as a fraction over a hundred rather than being spelled out, and the line ends with the word only so that nothing can be added after it.

The one word that divides the two styles

British English puts the word and between the hundreds and whatever follows. One hundred and twenty three. American English leaves it out. One hundred twenty three. Neither is wrong, and both are understood everywhere, but they are consistently different and people do argue about it.

The rule is narrower than people assume. The and only appears when there is a hundreds part and something after it. Two hundred is just two hundred in both styles. One thousand five hundred is the same in both. It is only when a remainder under a hundred follows something larger that the styles diverge, which is why 1234 differs and 1500 does not.

There is a second place it appears in British usage, and this one catches people. One million and five, not one million five. When the final group is under a hundred and there is a bigger part in front of it, the and goes in even though there are no hundreds involved. The tool handles that case, and a surprising number of converters do not.

Billions, and why the word once meant two things

This tool uses the short scale, where a billion is a thousand million. That is now standard in English everywhere, including Britain.

It was not always. Britain used the long scale for most of its history, in which a billion was a million million, a thousand times larger. The government formally switched to the short scale in 1974, and usage followed, but the long scale is still standard in much of continental Europe. If you are reading a historical British document, or translating from French, German or Spanish, a billion may not mean what you expect. A factor of a thousand is not a rounding difference.

A worked check you can repeat on paper

Take 1234. Split it into groups of three from the right: 1 and 234. The left group is one, and it sits in the thousands position, so that is one thousand. The right group is 234, which is two hundred, then a remainder of 34, which is thirty four.

In British style the and goes between the hundreds and the remainder: one thousand two hundred and thirty four. In American style it does not: one thousand two hundred thirty four. Same number, same groups, one word of difference.

Now try 1000005. The groups are 1 and 000 and 005. The middle group is zero so it is skipped entirely, which is why you never say one million zero thousand. The last group is five, under a hundred, with a bigger part in front, so British style gives one million and five.

Mistakes that catch people out

Hyphenating inconsistently. Formal style hyphenates the compound numbers from twenty one to ninety nine. This tool writes them as separate words, which is what most banks accept, but a style guide may ask for hyphens.

Writing the zero group. One million zero thousand five is not a thing. Empty groups are skipped, and that is why the and in one million and five is doing real work.

Assuming the figures win on a cheque. They do not. Where the written words and the numerals disagree, the words are what the bank honours in most jurisdictions, which is exactly why the words line exists.

Trusting very large numbers. A browser holds integers exactly only up to about nine quadrillion. Past that the digits themselves stop being reliable, so the tool refuses rather than printing words that do not match the figure.

Numbers written out in words

The numbers people look up most. Each opens the converter on that value with its own address.

How this was checked

The converter was tested against a list of known spellings covering every awkward shape: the teens, the round tens, numbers with a zero group in the middle, numbers ending under a hundred after a larger part, and the boundaries at a hundred, a thousand and a million. Both styles were checked separately, since the difference between them is the whole point.

The two cases most likely to be wrong were checked explicitly. One million and five confirms that an empty middle group is skipped and the trailing and still appears. Two thousand and twenty six confirms the same rule at a smaller scale, which matters because it is this year and people will look it up.

Related Calculators and Reference

• Roman Numeral Converter for the other way of writing a number without digits.
• Decimal to Fraction Converter for the fractional part that a cheque writes over a hundred.
• Scientific and Engineering Notation Converter for numbers past the point where words become useless.
• Loan Payment Calculator for working out the figure before you write it on anything.
• Morse Code Translator: spell out text as Morse code, with sound.