“Your contract asks for the amount in kanji numerals” or “you are writing a receipt in Japanese” - these are moments when kanji number conversion helps.
In this article, we explain how to convert numbers to kanji, covering the basic rules, the man/oku/cho (10^4) units, and tips for writing amounts in Japanese documents.
Kanji numeral basics
Kanji numerals represent numbers with Chinese characters:
| Number | Kanji |
|---|---|
| 0 | 零 |
| 1 | 一 |
| 2 | 二 |
| 3 | 三 |
| 4 | 四 |
| 5 | 五 |
| 6 | 六 |
| 7 | 七 |
| 8 | 八 |
| 9 | 九 |
| 10 | 十 |
Numbers above 10
Units 十 (10), 百 (100) and 千 (1,000) are combined:
- 11 → 十一
- 25 → 二十五
- 100 → 百
- 1,000 → 千
- 1,234 → 千二百三十四
Key point: Japanese never writes 一十 (one-ten) or 一百 (one-hundred) - just 十 and 百. The 一 is used only before 万, 億 and 兆.
The big units: man, oku, cho
Japanese groups digits in fours, not threes:
| Unit | Value |
|---|---|
| 万 (man) | 10,000 (10^4) |
| 億 (oku) | 100,000,000 (10^8) |
| 兆 (cho) | 1,000,000,000,000 (10^12) |
Examples:
- 12,345 → 一万二千三百四十五
- 123,456,789 → 一億二千三百四十五万六千七百八十九
- 1,234,567,890,000 → 一兆二千三百四十五億六千七百八十九万
Caution: Kanji grouping is by four digits (1万2345), not by three-digit commas (12,345). Don't let comma placement confuse you.
Writing amounts in documents
Contracts and receipts in Japan follow special rules:
- Append 円: amounts are written with the currency unit (e.g. 金三十万円)
- Use daiji (大字): formal characters that resist alteration
| Standard | Daiji |
|---|---|
| 一 | 壱 |
| 二 | 弐 |
| 三 | 参 |
| 十 | 拾 |
| 万 | 萬 |
How to convert numbers to kanji
The Tools Hub kanji number converter converts both ways instantly.
Enter a number
Type the number you want to convert (e.g. 12345).
Pick the direction
Choose "number to kanji" or "kanji to number".
Copy the result
Copy the converted value straight into your document.
The tool introduced in this article
Kanji Number Converter
Converts both ways, from zero up to cho (10^16). All in your browser with no uploads.
Summary
- Kanji numerals use the units 十, 百, 千, 万, 億 and 兆
- Grouping changes every four digits (10,000 = 一万)
- Formal documents use daiji characters (壱, 弐, 参)
- A converter helps avoid mistakes in both directions
- The Tools Hub converter works entirely in your browser
Next time you need kanji numerals, use the steps above or the Tools Hub kanji number converter.
FAQ
How do I convert numbers to kanji?
Group the digits in fours and read each group with its unit. Example: 12345 → 一万二千三百四十五.
Is the 一 in 一万 necessary?
Yes. The 一 appears before 万, 億 and 兆 (一万, 一億, 一兆), but not before 十, 百 or 千.
What is daiji (大字)?
Formal kanji numerals used to prevent alteration: 一→壱, 二→弐, 三→参, 十→拾. Used in contracts and financial documents.
Does it support very large numbers?
Yes, from zero up to cho (10^16). Suitable for amounts and statistics.
