Last updated 28 August 2026
Where written numbers still matter
Writing an amount in words is a safeguard rather than a formality. Digits can be altered with a stroke of a pen; words cannot be extended without it being obvious. That is why cheques, contracts and formal invoices carry both, and why the two are expected to agree exactly. The wording conventions differ by region in one small but persistent way: British English inserts "and" before the final part of a number under a thousand, so 105 reads "one hundred and five", while American English writes "one hundred five". Neither is wrong, but mixing them within one document looks careless, so the style is selectable here.
Common questions
What is the difference between the British and American styles?
Only the word “and”. British English writes 105 as “one hundred and five”; American English writes “one hundred five”. The difference appears wherever a hundreds figure is followed by a smaller part.
How should an amount be written on a cheque?
Choose a currency above and the output follows the usual convention — the whole amount in words followed by the currency name, then the fractional part. Practice varies slightly by bank and country, so check anything unusual against your own bank's guidance.
How large a number can it convert?
Up to the quintillions, using the short scale where a billion is a thousand million. Beyond that, ordinary number handling loses precision, so very large values are declined rather than converted inaccurately.
Does it handle negative numbers and decimals?
Yes. Negatives are prefixed with “minus”, and decimals are read out digit by digit after “point” unless a currency is selected, in which case the fractional part is treated as cents or pence.