Number to Words Converter
English
Japanese (kanji)
Daiji (formal / check writing)
How to Use
Type or paste a number in the input field. The tool instantly converts it to three formats: standard English words (e.g. "one thousand two hundred thirty-four"), Japanese kanji numerals (e.g. 千二百三十四), and formal daiji (e.g. 壱阡弐百参拾四 — used on checks, contracts, and receipts in Japan to prevent alteration). Each result has a copy button so you can paste it straight into a document.
What This Tool Does
Converting numbers into words is a common task when writing checks, legal documents, academic papers, or practicing English and Japanese. Each locale has its own conventions — English uses "one thousand" while Japanese mostly omits 一 and writes 千 directly. Daiji (大字) is the Japanese system of complex kanji used on formal financial documents because the simpler digits (一, 二, 三) can be easily altered with a pen stroke.
Supported Range
This tool accepts any integer from −999,999,999,999,999 to +999,999,999,999,999 (below 10^15), and decimals where the fractional part is read digit by digit. Numbers that are too large, non-numeric tokens, or expressions are not accepted — only plain decimal numbers. The English output uses short-scale naming (thousand, million, billion, trillion). The Japanese output uses the myriad system (万, 億, 兆, 京).
Common Use Cases
- Writing a check or invoice where the amount must be spelled out in words.
- Filling out Japanese forms or receipts that require 漢数字 or 大字 representation.
- Academic and legal writing where numbers must appear as words.
- Teaching or learning English/Japanese numerals.
- Accessibility use — screen-reader-friendly rendering of numeric values.
Tips
- Use commas or spaces between words, not hyphens — "forty-two" is the only hyphenated form in English.
- Daiji (壱, 弐, 参, 拾, 阡, 萬) is required on Japanese checks and some contracts because simpler kanji can be forged.
- Decimals are read digit-by-digit after the decimal point (3.14 → "three point one four").
- Negative numbers are prefixed with "negative" in English and マイナス in Japanese.
- For whole-yen amounts on a check, use 金 and 圓 around the daiji (e.g. 金壱阡圓).
Privacy
All conversions happen in your browser. The numbers you enter are never sent to any server or stored anywhere.
FAQ
What is the difference between Japanese kanji numerals and daiji?
Kanji numerals are the everyday form, like 千二百三十四. Daiji uses complex characters such as 壱, 弐, 参, 拾, 阡, and 萬 and is the formal form used on checks and contracts to prevent figures from being altered. This tool outputs both forms for the same number at once.
If I enter an amount, is it sent to a server?
No, it is safe. Conversion to English words, kanji, and daiji all happens in your browser, and the numbers you enter are never sent to or stored on a server. You can safely convert sensitive figures such as invoice amounts.
How large a number can it convert?
It handles integers from −999,999,999,999,999 to +999,999,999,999,999 (below 10^15). Numbers beyond that range, expressions, and non-numeric strings cannot be converted and will show an error.
Can it convert decimals and negative numbers?
Yes. Decimals are read digit by digit after the point (3.14 → "three point one four" / 三点一四). Negative numbers are prefixed with "negative" in English and マイナス in Japanese.
Any tips for using it on checks or receipts?
To prevent tampering, Japanese convention writes amounts in daiji wrapped with 金 and 圓 (e.g. 金壱阡圓). On English checks, separate words with spaces; the only hyphen is in compound numbers like "forty-two."