Number to Words Converter

This calculator converts numerical digits into their written English form, following UK conventions. It uses "and" before the tens (e.g. "one hundred and twenty-three") and supports values up to trillions. It is most commonly used when writing cheques or legal documents where the amount must be spelled out.

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 is no longer in standard use. The calculator follows modern UK usage throughout.

UK number-to-words conventions. British English uses 'and' after hundreds: 'one hundred and twenty-five'. US drops 'and' — 'one hundred twenty-five'. 1,000,000 = 'one million'. UK abandoned long scale (billion = 10^12) in 1974 — now uses short scale: billion = 10^9, trillion = 10^12, quadrillion = 10^15. Legal documents: figure written twice (numerals + words) to prevent fraud: 'Two thousand five hundred pounds (£2,500.00)'.

Cheque writing — official UK format. Convention: write pence as fraction or 'only'. £127.50 → 'One hundred and twenty-seven pounds and fifty pence only' or '...£127.50 only'. Draw line through unused space to prevent alteration. Banks reject cheques where numerals and words disagree — words take legal precedence. Cheques valid 6 months from date of issue. Scheduled for phaseout but no firm UK date — still widely used by HMRC, councils, schools.

Hyphenation rules. Hyphenate compound numbers 21-99: twenty-one, thirty-five, ninety-nine. Larger groups separated by spaces: 'three hundred and forty-five thousand, six hundred and twenty-one'. No hyphens between hundred/thousand and what follows: 'two hundred thousand' (not 'two-hundred-thousand'). Comma usage debated — Oxford style uses comma; AP omits. Ordinals: 'twenty-first' (hyphenated), 'one hundredth' (not hyphenated).

When to use words instead of digits. Style guides (Oxford, Guardian, Times): words for one to nine; digits for 10+. Always digits: ages (5-year-old), measurements (3 kg), percentages (8%), times (3pm), money (£25), tables. Always words: at start of sentence ('Twenty-three people attended'), approximations ('about a thousand'), fractions in prose ('two-thirds of voters'). Inconsistency within one sentence is the cardinal sin.

UK historical numerical writing. Predecimal money pre-1971: written £.s.d. or 'pounds, shillings, pence'. 1 pound = 20 shillings; 1 shilling = 12 pence. £4 12s 6d = '£4/12/6'. Decimalisation 15 Feb 1971: simplified to current 100p per £. Years: pre-2000 often '1995' or 'nineteen ninety-five'; post-2000 'two thousand and twenty-six' or '2026'. Dates UK format: DD MMM YYYY (15 March 2026); US format MMM DD, YYYY (March 15, 2026).