Number to Words Converter

This calculator converts numerical digits into their written English form, following UK conventions. It uses and before the tens, giving one hundred and twenty-three, and supports values up to trillions. American English drops that and, writing one hundred twenty-five where British English writes one hundred and twenty-five. The tool is most commonly used when writing cheques or legal documents where the amount must be spelled out in full.

UK English uses billion to mean one thousand million (1,000,000,000), the same as US English. The older British long scale, where a billion meant a million million, was abandoned in 1974 and is no longer in standard use. On the modern short scale a billion is 10^9, a trillion is 10^12 and a quadrillion is 10^15. The calculator follows modern UK usage throughout, so a converted figure reads the way a British reader expects it to.

Legal documents write the figure twice, in numerals and in words, because the duplication makes alteration much harder. Two thousand five hundred pounds (£2,500.00) is the standard form. On a cheque, pence go in as a fraction or with the word only appended, so £127.50 becomes one hundred and twenty-seven pounds and fifty pence only. Draw a line through any unused space to stop something being added later. Where the numerals and the words disagree, banks reject the cheque, and the words take legal precedence.

Cheques stay valid for 6 months from the date of issue, which is UK banking practice rather than law. They have been scheduled for phaseout for some time without a firm UK date, and they remain in wide use by HMRC, councils and schools, which is why the written format still matters. Take £2,547.83 as an example. The pounds read two thousand five hundred and forty-seven, the pence read eighty-three, and joining the two gives the full cheque line.

Hyphens go into compound numbers from 21 to 99, so twenty-one, thirty-five and ninety-nine all take one. Larger groups are separated by spaces instead, giving three hundred and forty-five thousand, six hundred and twenty-one, and there is no hyphen between hundred or thousand and whatever follows, so two hundred thousand stays open. Whether that comma belongs there is genuinely disputed, since Oxford style uses it and AP omits it. Ordinals follow the same pattern, with twenty-first hyphenated and one hundredth left alone.

Style guides including Oxford, the Guardian and The Times write whole numbers from one to nine in words and use digits from 10 upwards in flowing text. Digits always win for ages (5-year-old), measurements (3 kg), percentages (8%), times (3pm), money (£25) and anything set in a table. Words always win at the start of a sentence, as in Twenty-three people attended, and for approximations such as about a thousand or fractions in prose such as two-thirds of voters. Mixing the two conventions inside a single sentence is the one thing every style guide condemns.

British numerals looked very different before decimalisation on 15 February 1971. Money was written as pounds, shillings and pence, with 20 shillings to the pound and 12 pence to the shilling, so an amount appeared as £4 12s 6d or £4/12/6, and decimalisation replaced that with 100p to the pound. Years follow their own habit, with pre-2000 dates usually spoken as nineteen ninety-five and later ones as two thousand and twenty-six. Date order differs across the Atlantic as well, with 15 March 2026 in British form and March 15, 2026 in American.