Number to Words Converter
Convert any number to its written English form. Free, instant, supports large numbers.
When to Write Numbers as Words vs Numerals
Style guides agree on a few core rules: spell out numbers one through nine (or one through ten in some guides) and use numerals from 10 (or 11) upward. Always use numerals for measurements with units (5 km, 3 hours), percentages (8%), dates and financial figures. Spell out numbers that start a sentence — or rewrite the sentence to avoid starting with a numeral. When two numbers appear together, alternate for clarity: twelve 50-page reports, not 12 50-page reports.
Writing Numbers in Formal Documents
In legal contracts, cheques and invoices it is standard to write amounts in both numerals and words: $1,250.00 (One Thousand Two Hundred Fifty Dollars and 00/100). This dual format prevents tampering and resolves ambiguity. Compound numbers from 21–99 always use a hyphen: forty-two, not "forty two". Ordinals follow the same pattern: twenty-first, forty-third.
Large Number Scale (Short Scale — US/UK)
| Numeral | Words | Powers of 10 |
|---|---|---|
| 1,000 | One thousand | 10³ |
| 1,000,000 | One million | 10⁶ |
| 1,000,000,000 | One billion | 10⁹ |
| 1,000,000,000,000 | One trillion | 10¹² |
| 1,000,000,000,000,000 | One quadrillion | 10¹⁵ |
British vs American English Differences
In the short scale (used in the US, UK since 1974, and most English-speaking countries), a billion is 10⁹ (one thousand million). The long scale, still used in some European countries, defines a billion as 10¹² (one million million). This tool uses the short scale. British English also prefers "nought" for zero in spoken contexts and spells compound hundreds differently in some registers: one hundred and five (with "and") vs American one hundred five.