Number to Words Converter

Type any number and instantly read it in English words — from single digits up to hundreds of trillions, including negatives and two-digit decimals. It is handy for writing checks, legal documents, and invoices, or for learning how large English numbers are pronounced. Everything runs locally in your browser.

Supported Input Format

The input validator is deliberately strict so the words are always unambiguous. It accepts:

• An optional leading minus sign.
• Between 1 and 15 integer digits.
• An optional decimal point followed by 1 or 2 digits.

That means 42, -42, 0.5, 1234.56, and 999999999999999 are all valid. Rejected forms include .5 (no leading digit), 1. (no digit after the point), 1,000 (comma), 1 000 (space), +7 (plus sign), 1e6 (exponent), and 1.234 (three decimals). The tool converts as you type, and a message appears when the input does not match the pattern or exceeds the supported range.

How the Conversion Works

English numbers are built in blocks of three digits. The algorithm splits the input into a whole part and a fractional part, then reads the whole part from the largest scale down:

1. Round the value to two decimal places to remove floating-point artifacts.
2. Walk the scales trillion, billion, million, thousand. For each, take the group of up to three digits at that scale and convert it with the same hundreds-tens-ones rules.
3. Convert any remaining group below one thousand.
4. If a fractional part remains, append “point” and speak each remaining decimal digit individually.

Within a three-digit group, hundreds come first, then the tens and ones joined by a hyphen (twenty-one, ninety-nine). Teens are irregular and handled as a single word block (eleven through nineteen). The style is American English, so there is no “and” inside hundreds: 123 is “one hundred twenty-three”, not “one hundred and twenty-three”.

Worked Examples

Input	Output
1,234,567	one million two hundred thirty-four thousand five hundred sixty-seven
1000000	one million
3.5	three point five
-0.05	negative zero point zero five
999999999999999	nine hundred ninety-nine trillion nine hundred ninety-nine billion nine hundred ninety-nine million nine hundred ninety-nine thousand nine hundred ninety-nine

The 3.5 example shows the digit-by-digit decimal rule: it is “three point five”, never “three and a half” or “three point fifty”. The -0.05 case shows both the negative prefix and a decimal that starts with zero, which is spoken as “zero five”. The 15-digit case is the upper bound and demonstrates each scale word in turn.

Language Support and What It Does Not Do

The conversion is English cardinal words only. That is easy to miss because the site is available in Chinese and German: those locales translate the page labels, buttons, and help text, but the library that produces the words is not localized. A Chinese-language visitor who types 42 still sees “forty-two” rather than “四十二”. If you need number words in another language, this tool is not the right source for that text.

• No currency words. It produces “one thousand two hundred thirty-four point five six”, not “one thousand two hundred thirty-four dollars and fifty-six cents”.
• No ordinal forms. There is no “first”, “second”, or “twenty-first” output; the result is always cardinal.
• No leading-zero preservation. 007 becomes “seven” because the value is parsed as a number.
• No fractions beyond two decimals. Three or more decimal digits are rejected by the input validator rather than rounded.
• No scientific or formatted input. Commas, unit suffixes, and exponents are not accepted.
• No British “and”. Hundreds are written in the American style throughout.

Reading Decimals and British Versus American Style

The decimal handling is the part most people get wrong when writing amounts by hand. The tool does not read the fractional part as a whole number; it reads each digit. So 1234.56 becomes “one thousand two hundred thirty-four point five six”, and 0.05 becomes “zero point zero five”. A single decimal digit is spoken alone: 3.5 is “three point five”. A trailing zero is dropped, so 2.10 becomes “two point one” — technically the value of 2.1, which is why two-decimal inputs like 2.10 still work even though the final zero disappears.

This is the convention banks want on checks: the dollars in words, then the cents as a two-digit group, like “one thousand two hundred thirty-four and 56/100”. The calculator gives you the words portion; you still add the currency words and the fractional notation yourself. If you paste in a value with three decimals, the validator rejects it rather than rounding, so round your amount to two places before converting.

English number words differ across the Atlantic in one visible way: British English inserts “and” before the tens or units when a hundred is present. British speakers say “one hundred and twenty-three”; the American convention this tool follows is “one hundred twenty-three”. The difference sounds small, but legal and financial writing often has a house style, and a document that mixes the two looks inconsistent. If your organization requires the British form, add “and” manually in the hundreds positions — there is no toggle for it here. Beyond that single word, the two conventions agree: the same scale words, the same hyphen between tens and ones, and the same digit-by-digit decimals.

Practical Uses

Banks and landlords often require the amount on a check to be written in words as well as figures, and legal contracts spell out sums to make tampering harder. Invoices frequently carry a words line for the same reason. Teachers and language learners use the tool to check how large numbers are read aloud, and accessibility workflows convert figures to text so screen readers and text-to-speech engines pronounce them correctly. Keep amounts to two decimal places to mirror how money is normally written, and remember the output is a phrase — you still add the currency name yourself.

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