About This Tool
Writing numbers as words is required in legal documents, checks, formal letters, and academic papers. Banks require the dollar amount on checks to be written in words to prevent tampering, and many style guides mandate spelling out numbers under a certain threshold. Doing this conversion by hand is straightforward for small values but gets tricky with large numbers, decimals, and edge cases like "eleven" versus "onety-one" (which is not a real word, of course). This Number to Words Converter instantly transforms any numeric value into its English word equivalent. It handles whole numbers up to the quintillions, decimal values (spelled out digit by digit after the point), negative numbers, and two specialized modes: a currency format designed for check writing that produces output like "One thousand two hundred thirty-four dollars and 56/100," and an ordinal mode that generates words like "first," "twenty-third," or "one hundred forty-fourth." Type or paste your number and the result updates in real time with no page reloads or signups needed.
How the Number to Words Conversion Works
English number naming follows a consistent pattern based on groups of three digits (thousands, millions, billions, and so on). The conversion process breaks a number into these three-digit groups from right to left, converts each group independently, and then attaches the appropriate scale word.
For example, 1,234,567 splits into: 1 (million), 234 (thousand), 567. Each chunk follows the same rules: hundreds digit + "hundred" + tens and ones. The result is "one million two hundred thirty-four thousand five hundred sixty-seven."
Special cases exist for the teens (11 through 19), which have unique names rather than following the tens+ones pattern. The converter handles all of these correctly, including zero (which is simply "zero" as a standalone value).
Currency Mode for Check Writing
When writing checks or formal payment documents, the standard format spells out the dollar amount and expresses cents as a fraction over 100. For example:
- $1,234.56 becomes "One thousand two hundred thirty-four dollars and 56/100"
- $500.00 becomes "Five hundred dollars and 00/100"
- $0.99 becomes "Zero dollars and 99/100"
This format prevents fraud because words are harder to alter than digits. Banks and financial institutions specifically look for the written amount to match the numeric amount on the check. The converter pads cents to two digits automatically so "5 cents" becomes "05/100" as required.
Ordinal Numbers Explained
Ordinal numbers indicate position or rank: first, second, third, and so on. English ordinals follow patterns but have many irregular forms:
- Unique forms: first, second, third, fifth, eighth, ninth, twelfth
- Regular -th suffix: fourth, sixth, seventh, tenth, eleventh
- Tens ending in -y: change to -ieth (twenty becomes twentieth, thirty becomes thirtieth)
- Compound ordinals: only the last word changes (twenty-first, one hundred thirty-fourth)
The ordinal mode handles all of these patterns correctly. Enter any whole number and the converter produces the properly formed ordinal word, useful for ranking lists, dates, and formal descriptions.
When to Spell Out Numbers vs. Use Digits
Style guides vary, but common conventions include:
- AP Style: Spell out one through nine, use digits for 10 and above.
- Chicago Manual of Style: Spell out zero through one hundred, plus round large numbers like "two hundred" or "five thousand."
- Legal documents: Often spell out the number followed by digits in parentheses: "Five Hundred (500) Dollars."
- Scientific writing: Use digits for measurements and data, words for general quantities.
Always spell out a number that begins a sentence, regardless of its size. If the number is unwieldy when written out (like 1,247,893), consider restructuring the sentence so the number falls later.
Handling Large Numbers and Decimals
The converter supports the standard English naming scale used in the United States and modern British English:
- Thousand = 103
- Million = 106
- Billion = 109
- Trillion = 1012
- Quadrillion = 1015
- Quintillion = 1018
Decimal values are expressed as the integer part in words, followed by "point" and each decimal digit spelled individually. For instance, 3.14159 becomes "three point one four one five nine." This is the standard mathematical reading convention and avoids ambiguity.
Frequently Asked Questions
How does the converter handle very large numbers?
The converter supports numbers up to the quintillions (10^18). It breaks the number into groups of three digits from right to left, converts each group to words, and appends the appropriate scale name (thousand, million, billion, trillion, quadrillion, quintillion). Numbers beyond this range may lose precision due to floating-point limitations.
What is the correct way to write a check amount in words?
Write the dollar amount in words, followed by "and" and the cents as a fraction over 100. For example, $2,350.75 should be written as "Two thousand three hundred fifty dollars and 75/100." Draw a line from the end of the text to the printed "Dollars" on the check to prevent additions. Always match the written amount to the numeric amount in the box.
Does the converter support languages other than English?
This converter generates English words only. Number word systems vary significantly between languages. French uses a base-20 pattern for 70-99, German inverts tens and ones ("einundzwanzig" for 21), and many Asian languages group digits in sets of four rather than three. Each language would require a separate conversion engine.
Why are some ordinal numbers irregular in English?
English ordinals inherited irregular forms from Old English and Germanic roots. "First," "second," and "third" come from entirely different word origins than their cardinal counterparts. "Fifth" and "twelfth" modify their base words for easier pronunciation. These irregularities have been preserved through centuries of usage despite being inconsistent with the regular "-th" suffix pattern.
How are negative numbers expressed in words?
Negative numbers are prefixed with the word "negative." For example, -42 becomes "negative forty-two." In some mathematical and scientific contexts, "minus" is used instead of "negative," but "negative" is the more common convention in everyday English and is what this converter produces.
Is there a difference between American and British number naming?
Historically, yes. The British "long scale" used "billion" to mean 10^12 (a million millions), while the American "short scale" uses "billion" for 10^9 (a thousand millions). However, the British government officially adopted the short scale in 1974, and most modern English-language contexts now use the American convention. This converter uses the short scale.